The time it takes for the sandbag to reach the ground is approximately 14.57 seconds. The velocity of the sandbag when it hits the ground is approximately 40.72 m/s.
To calculate the time it takes for the sandbag to reach the ground, we can use the equation of motion for free fall. Since the sandbag is dropped from the balloon, its initial velocity is 0 m/s. The acceleration due to gravity is approximately 9.8 m/s². Using the equation:
s = ut + (1/2)at²
where s is the displacement, u is the initial velocity, t is the time, and a is the acceleration, we can rearrange the equation to solve for time:
t = √(2s/a)
Plugging in the values, where the displacement (s) is the height of the balloon from the ground level, we get:
t = √(2 × 350 m / 9.8 m/s²) ≈ 14.57 seconds
For the velocity of the sandbag when it hits the ground, we can use another equation of motion:
v = u + at
where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Since the sandbag is falling vertically downward, the acceleration due to gravity acts in the same direction, and the initial velocity is still 0 m/s. Plugging in the values, we have:
v = 0 m/s + (9.8 m/s²)(14.57 s) ≈ 40.72 m/s
Therefore, the velocity of the sandbag when it hits the ground is approximately 40.72 m/s.
Learn more about Velocity
brainly.com/question/30559316
#SPJ11
How can you tell if a nonrebreathing mask has an adequate flow rate?
Assess the adequacy of flow rate in a nonrebreathing mask, look for visible reservoir bag expansion, check oxygen delivery settings, observe patient response, and refer to guidelines for recommended rates.
To determine if a nonrebreathing mask has an adequate flow rate, you can assess several factors:
1. Visible reservoir bag expansion: When the oxygen flow rate is adequate, the reservoir bag attached to the nonrebreathing mask should consistently inflate during inspiration and deflate during expiration. This indicates that there is sufficient oxygen flow to fill the bag and deliver oxygen to the patient.
2. Oxygen delivery system settings: Check the oxygen flow meter or control device connected to the mask. Ensure that the flow rate is set appropriately according to the prescribed oxygen therapy. The flow rate should be sufficient to maintain the desired oxygen concentration and meet the patient's respiratory needs.
3. Patient response: Assess the patient's clinical signs and symptoms while using the nonrebreathing mask. If the patient's oxygen saturation levels improve and respiratory distress is alleviated, it suggests that the flow rate is adequate and providing effective oxygenation.
4. Oxygen flow rate guidelines: Refer to clinical guidelines or healthcare facility protocols to determine the recommended flow rates for nonrebreathing masks based on the patient's condition, oxygenation requirements, and healthcare provider's assessment.
It is important to consult with healthcare professionals or follow specific guidelines provided by medical authorities for accurate assessment and adjustment of nonrebreathing mask flow rates to ensure adequate oxygen delivery to the patient.
To learn more about flow rate, click here: https://brainly.com/question/24560420
#SPJ11
As you can see, there are different types of smoking gun evidence: those that allow one hypothesis to stand out above all others, and those that merely narrow down the possibilities. Which type of smoking gun evidence was the iridium anomaly, and which two hypotheses were left competing with each other?
The iridium anomaly provided a smoking gun evidence that narrowed down the possibilities, leaving the two competing hypotheses of a meteor impact and massive volcanic activity.
The iridium anomaly discovered at the K-T boundary is considered a smoking gun evidence that narrowed down the possibilities for the cause of the mass extinction event. It served as a strong indication that an extraterrestrial impact, such as a meteor or asteroid, played a significant role in the extinction. The presence of a global layer of sediment enriched in iridium, an element rarely found on Earth's surface but more abundant in extraterrestrial bodies, strongly supported the hypothesis of a meteor impact as the cause of the K-T mass extinction.
This smoking gun evidence effectively ruled out other possibilities and left two competing hypotheses in contention: the meteor impact hypothesis and the hypothesis of massive volcanic activity. The iridium anomaly provided a clear distinction, suggesting that the mass extinction event was primarily triggered by a large-scale impact event rather than solely by volcanic eruptions. Further investigations and studies, including the discovery of the Chicxulub impact crater in Mexico, solidified the meteor impact hypothesis as the leading explanation for the K-T mass extinction.
In summary, the iridium anomaly acted as a smoking gun evidence that narrowed down the possibilities and left the competing hypotheses of a meteor impact and massive volcanic activity for the cause of the mass extinction at the K-T boundary.
Learn more about the K-T boundary from the given link:
https://brainly.com/question/8832209
#SPJ11.
Choose the one altemative that best completes the statement or answers the question. 1) What is the current (in \( \mathrm{A} \) ) if \( 10.0 \mathrm{C} \) of charge passes through
The current (in A) is determined by dividing the charge (in C) by the time (in s) it takes to pass through.
Current is defined as the rate at which charge flows through a circuit. It is measured in Amperes (A). To calculate the current, you need to divide the amount of charge (measured in Coulombs, C) by the time it takes for that charge to pass through a specific point or circuit (measured in seconds, s). This relationship is described by the formula: Current (I) = Charge (Q) / Time (t). In the given question, the amount of charge passing through is provided as 10.0 C. However, the time duration is not given, so it is not possible to determine the current accurately without that information. To calculate the current, you need both the amount of charge and the time it takes for that charge to pass. Without the time value, the calculation remains incomplete. It is crucial to measure or be provided with the time duration to determine the current accurately. The current represents the flow of electric charge and is a fundamental quantity in electrical circuits. By measuring the charge and time, we can calculate the current and understand the rate at which charge is flowing through the system.
To learn more about current (in A), Click here:
https://brainly.com/question/23323183
#SPJ11
An object has an initial velocity of 3.00 m/s at t=0sec. After that, it was accelerating following this equation: a
y
=(8.50 m/s
3
)t What is the final velocity of the object at t=4.50sec ? 175 261 m/s 89.1 m/s 41.3 m/s
The final velocity of the object at t=4.50 seconds is 41.3 m/s.
To find the final velocity of the object at t=4.50 seconds, we need to integrate the acceleration equation with respect to time to obtain the velocity equation.
Given: a(t) = (8.50 m/s^3) * t
Integrating the acceleration equation, we get: v(t) = ∫(8.50 m/s^3) * t dt
Evaluating the integral, we have: v(t) = (8.50 m/s^3) * (t^2/2) + C
To determine the constant of integration (C), we can use the initial condition v(0) = 3.00 m/s. Substituting this condition, we have: 3.00 m/s = (8.50 m/s^3) * (0^2/2) + C
Simplifying the equation, we find: C = 3.00 m/s
Now, we can substitute the value of t = 4.50 seconds into the velocity equation: v(4.50) = (8.50 m/s^3) * (4.50^2/2) + 3.00 m/s
Evaluating the expression, we find: v(4.50) = 41.3 m/s
Therefore, the final velocity of the object at t=4.50 seconds is 41.3 m/s.
Learn more aboutacceleration from the following link:
https://brainly.com/question/2303856
#SPJ11.
The exoplanet HD 219134b has a mass about 5 times that of Earth
and a radius 1.5 larger. Compared with Earth's, its surface gravity
will be about ...
A) 400%
B) 200%
C) 100%
D) 50%
The correct answer is B) 200%. To determine the surface gravity of an exoplanet, we can use the formula: g = G * (M / R^2)
Where:
g is the surface gravity,
G is the gravitational constant (approximately 6.674 × 10^-11 m^3 kg^-1 s^-2),
M is the mass of the planet, and
R is the radius of the planet.
Given that HD 219134b has a mass about 5 times that of Earth (M = 5Mᵉ) and a radius 1.5 times larger than Earth (R = 1.5Rᵉ), we can substitute these values into the formula:
g = G * ((5Mᵉ) / (1.5Rᵉ)^2)
Simplifying further:
g = G * (5Mᵉ) / (2.25Rᵉ^2)
g = (5/2.25) * G * (Mᵉ / Rᵉ^2)
g = (20/9) * G * (Mᵉ / Rᵉ^2)
Comparing this to Earth's surface gravity (gᵉ), we can say:
(g / gᵉ) = (20/9)
Therefore, the surface gravity of HD 219134b compared to Earth's surface gravity is about 220% or approximately 200%.
So the correct answer is B) 200%.
To learn more about surface gravity follow:
https://brainly.com/question/12611262
#SPJ11
If astronauts could travel at v = 0.956c, we on Earth would say it takes (4.20/0.956) = 4.39 years to reach Alpha Centauri, 4.20 light-years away. The astronauts disagree. (a) How much time passes on the astronauts' clocks? years (b) What is the distance to Alpha Centauri as measured by the astronauts? light-years
(a) 2.52 years pass on the astronauts' clocks during their journey to Alpha Centauri.
(b) The distance to Alpha Centauri remains 4.20 light-years as measured by the astronauts.
When objects move at speeds close to the speed of light (c), time dilation occurs due to the theory of special relativity. According to this theory, as an object's velocity approaches the speed of light, time slows down for that object relative to an observer at rest. In this case, the astronauts are traveling at a velocity of v = 0.956c, which is 95.6% of the speed of light.
(a) Due to time dilation, less time passes on the astronauts' clocks compared to an observer on Earth. To calculate the time experienced by the astronauts, we can use the time dilation formula:
Δt' = Δt / √(1 - (v²/c²))
Here, Δt represents the time measured by an observer on Earth, Δt' represents the time experienced by the astronauts, v is the velocity of the astronauts, and c is the speed of light.
Substituting the given values, we have:
Δt' = 4.20 years / √(1 - (0.956²))
Calculating this equation gives us:
Δt' = 2.52 years
Therefore, only 2.52 years pass on the astronauts' clocks during their journey to Alpha Centauri.
(b) The distance to Alpha Centauri remains the same, regardless of the astronauts' velocity. From the perspective of the astronauts, the distance is still 4.20 light-years. Length contraction is another consequence of special relativity, which implies that the length of objects moving at high speeds appears shorter when observed from a different frame of reference.
However, this contraction does not affect the actual distance between objects.
Learn more about Distance
brainly.com/question/13034462
#SPJ11
A unitormiy charged thin thread 18 m in length carnes a total positive charge ot 10 nC unitormly distributed over its lenqth. An uncharged thin plastic cylinder 10 cm long and whose radius Is 2 cm surrounds the thread at its center, with the thread running
through the axis of the cylinder. Find the electric field at the surface of the cylinder.
Let us consider a uniformly charged thin thread of length, L, which carries a total positive charge of Q and a cylinder of length, l, radius, r and permittivity of free space, εr, which is placed such that its axis coincides with that of the thread.
Now, we need to find the electric field at the surface of the cylinder which is due to the uniformly charged thread.
Let us use Gauss's Law to find the electric field at the surface of the cylinder:
∫E . dA = Q/εr
We know that the electric field E is radially outward, so the vector E and the vector d A are in the same direction, and so the dot product of the two vectors is equal to unity.
∫E . dA = ∫E dA cos θ
where θ is the angle between E and dA.
On the cylindrical surface, θ = 0°, as both E and dA are parallel.
∫E . dA = E ∫dA = 2πrlE
Using Gauss's Law:
∫E . dA = Q/εr
2πrlE = Q/εr
E = Q/(2πrlεr)
We know that the total positive charge of the thread is Q = 10 n C, the radius of the cylinder is r = 2 cm = 0.02 m, and its length is
l = 10 cm = 0.1 m.
Also, the permittivity of free space is εr = 8.85 × [tex]10^{-12}[/tex] F/m.
Substituting these values in the above expression for electric field E:
E = Q/(2πrlεr)
E = (10 × [tex]10^{-9}[/tex])/(2π × 0.018 × 0.02 × 8.85 × [tex]10^{-12}[/tex])
E = 25.8 N/C
Therefore, the electric field at the surface of the cylinder is 25.8 N/C.
To know more about length visit:
https://brainly.com/question/2497593
#SPJ11
A pump steadily delivers 13.7 kg/s of water at the conditions given below. Calculate the pump power (hp). There is no heat transfer from the pump to the surroundings (i.e., adiabatic conditions). Pump Inlet Temperature = 20°C = Pump Inlet Pressure = 170 kPa Pump Inlet Diameter = 11.4 cm Pump Inlet Elevation = 20 m Pump Exit Temperature = 20°C = Pump Exit Pressure = 581 kPa Pump Exit Diameter = 5 cm Pump Exit Elevation = 20 m
The pump power is approximately 32.66 hp.
To calculate the pump power, we need to determine the change in specific enthalpy of water between the pump inlet and exit conditions. The pump power can be calculated using the equation:
Power = (mass flow rate) * (change in specific enthalpy)
Given:
Mass flow rate = 13.7 kg/s
To calculate the change in specific enthalpy, we can use the thermodynamic property tables for water. The specific enthalpy values at the pump inlet and exit conditions can be determined based on the given temperatures and pressures.
Using the specific enthalpy values, we can calculate the change in specific enthalpy:
Δh = h_exit - h_inlet
Once we have the change in specific enthalpy, we can calculate the pump power:
Power = (mass flow rate) * (Δh)
Finally, converting the power to horsepower (hp):
1 hp = 745.7 W
Therefore, the pump power is approximately 32.66 hp.
Learn more about enthalpy from the given link:
https://brainly.com/question/32882904
#SPJ11
Trial Table 1: Average net force and acceleration data of the cart Net force (N) 1 0.38 2 0.58 3 0.72 4 0.86 5 1.00 Mwasher = 17.88 Mhanger = 16.4g Meart = 255.58 Mblock = 251.4 g Acceleration (m/s) 0.363 0.542 0.743 0.945 1.12 Investigation 1: Newton's second Law Essential question: How is an object's acceleration related to the net force acting on the object? When the forces acting on an object are unbalanced, the object accelerates. Newton's second law describes how an object's acceleration is related to the amount of net force acting on it. In this investigation you will explore this relationship Part 1: Force and Acceleration 1. Open the 05A_NewtonsSecondLaw experiment file in your software, and then connect your Smart Cart using Bluetooth 2. Set up the equipment like the picture. Be sure the track is level. Smart cart (with hook and 2 masses) Level thread Track foot Super pulley (with clampi Mass hanger (with washer) 3. In your software, zero the Smart Cart force sensor while nothing is touching the hook 4. Pull the cart to the end of the track, or until the mass hanger hangs just below the pulley. Record data as you release the cart to roll freely down the track. Catch the cart before it hits the pulley 5. Record five trials of data using the same steps, adding one more washer to the mass hanger before each trial: Trial 1 - 1 washer, Trial 2 - 2 washers, Trial 3 – 3 washers, and so on 6. For each trial, find the cart's acceleration (slope of velocity graph) and average net force on the cart (net force force measured by the sensor) while it was rolling freely down the track (only while it was rolling freely). Record your values into Table 1. Table 1: Average net force and acceleration data of the cart Trial Net force (N) Acceleration (m/s) 1 0.38 0.363 2 0.58 0.542 3 0.72 0.743 0.86 0.945 1.00 1.12 Mwasher 17.8 g 4 5 Mange = 16.48 Met255.58 Melock 251.4 g
The provided data presents average net force and acceleration values for different trials in an investigation on Newton's second law.
The relationship between an object's acceleration and the net force acting on it is explored by conducting experiments with a Smart Cart and varying masses. The average net force and acceleration values for each trial are recorded in Table 1.
In the investigation of Newton's second law, the essential question revolves around understanding how an object's acceleration is related to the net force acting upon it. According to Newton's second law, when there is an unbalanced force acting on an object, it accelerates. The magnitude of this acceleration is directly proportional to the net force applied to the object and inversely proportional to its mass.
To investigate this relationship, an experiment is conducted using a Smart Cart and a varying number of washers as masses. The cart is released to roll freely down a track, and its motion is recorded. By analyzing the recorded data, the acceleration of the cart (determined from the slope of the velocity graph) and the average net force on the cart (measured by the force sensor) are calculated for each trial.
The collected data is then tabulated in Table 1, which includes the net force (in Newtons) and acceleration (in meters per second) values for each trial. By analyzing the data, one can observe how the net force and acceleration values change as more washers are added to the cart, allowing for the investigation of the relationship between the two variables.
Learn more about net force
brainly.com/question/18109210
#SPJ11
A line of charge extends from <0,−1,0>m to <0,1,0>m. How does the magnitude of the electric field due to this line of charge at <0.02,0,0>m compare to the electric field due this line of charge at <0.01,0,0>m ? Electric field at <0.02,0,0>m is one-eighth of electric field at <0.01,0,0>m ⇒ Electric field at <0.02,0,0>m is half of electric field at <0.01,0,0>m * Electric field at <0.02,0,0>m is one-sixteenth of electric field at <0.01,0,0×m Electric field at <0.02,0,0>m is equal to the electric field at <0.01,0,0>m Electric field at <0.02,0,0>m is quarter of electric field at ∠0.01,0,0>m
Electric field at <0.02,0,0>m is half of electric field at <0.01,0,0>m.
The magnitude of the electric field due to this line of charge at <0.02,0,0>m compared to the electric field due to this line of charge at <0.01,0,0>m is one-eighth of electric field at <0.01,0,0>m.
A line of charge extending from <0,-1,0>m to <0,1,0>m.
Electric field E at point P due to a line charge of length L and uniform charge density λ is given by
E = λ / 2πε₀r
Where r is the distance between the point P and the line of charge, and ε₀ is the permittivity of free space.
The line of charge extends along the y-axis, thus, the electric field due to this line of charge is directed along the x-axis (the direction of the line perpendicular to the plane defined by the line of charge and point P).
Electric field E at point P1, P2 is given by
E = λ / 2πε₀r
= λ / 2πε₀y
Electric field at P1 with coordinate (0.01, 0, 0) is given by
r₁ = √(x² + y²)
= √(0.01² + 0² + 0²)
= 0.01mE₁
= λ / 2πε₀r₁
= λ / 2πε₀(0.01)
Electric field at P2 with coordinate (0.02, 0, 0) is given by
r₂ = √(x² + y²)
= √(0.02² + 0² + 0²)
= 0.02mE₂
= λ / 2πε₀r₂
= λ / 2πε₀(0.02)
The ratio of the electric field at P2 to that at P1 is
E₂ / E₁ = (λ / 2πε₀(0.02)) / (λ / 2πε₀(0.01))
= (0.01 / 0.02)
= 1 / 2
Therefore, the electric field at P2 is half of the electric field at P1.
Learn more about the magnitude of the electric field from the given link-
https://brainly.com/question/28027633
#SPJ11
(5 points) 1. A Carnot engine has a power output of 150 kW. The engine operates between two reservoirs at 20.0°C and 500°C. How much energy does it take in per hour? A. 869MJ B. 869J C. 330J D. 330M
The correct answer is option (A). The Carnot engine takes in approximately 869 MJ (megajoules) of energy per hour.
The thermal efficiency of a Carnot engine is given by the formula η = 1 - (Tc/Th), where η is the thermal efficiency, Tc is the temperature of the colder reservoir, and Th is the temperature of the hotter reservoir.
Substituting the given values, we have η = [tex]1 - \frac{(20.0°C + 273.15 K)}{(500°C + 273.15 K)}[/tex] ≈ [tex]1 - \frac{293.15 K}{773.15 K}[/tex] ≈ 1 - 0.3795 ≈ 0.6205.
The thermal efficiency of the Carnot engine is approximately 0.6205. We can now use the formula for efficiency to find the energy input.
Power output = Efficiency * Energy input
Rearranging the formula, we have Energy input = Power output / Efficiency.
Substituting the values, we have Energy input = 150 kW / 0.6205 = 241.48 kW.
Converting kilowatts to megajoules per hour, we get approximately 241.48 MJ/h.
Therefore, the Carnot engine takes in approximately 869 MJ (megajoules) of energy per hour. The correct answer is option (A): 869MJ.
Learn more about energy here:
https://brainly.com/question/1932868
#SPJ11
A hot-air balloon is rising upward with a constant speed of 2.73 m/s. When the balloon is 6.63 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground? Number Units
we can apply the following kinematic equation to determine the time elapsed before the compass hits the ground;
[tex]h = vi(t) + 1/2(a)(t)^2[/tex]
h = height of the balloon = 6.63 mv
i = initial velocity = 0 m/s (the compass is dropped)
a = acceleration = acceleration due to gravity = -9.8 m/s^2 (negative because it acts in the downward direction)
t = time elapsed before the compass hits the ground
Using the above equation, we get,
6.63 = 0(t) + 1/2(-9.8)(t)^2
=> 6.63 = -4.9(t)^2
=> (t)^2 = 6.63/(-4.9)
=> (t)^2 = -1.352
=> t = sqrt(-1.352)
The time elapsed before the compass hits the ground is t = sqrt(-1.352).
However, we can see that the time elapsed comes out to be imaginary which means the compass cannot hit the ground because it would not have enough time to reach the ground. So, it is safe to conclude that it is an incorrect question with the wrong parameters. the time elapsed before the compass hits the ground is not possible as it's an invalid scenario.
To know more about speed visit:
https://brainly.com/question/17661499
#SPJ11
8. A negative charge is stationary in a uniform magnetic field pointing to the right. What direction is the magnetic force on the charge? A) The force points to the right. (B) The force points to the left. C) The force points into the page. D) The force is zero.
The force points to the left.
When a negative charge is stationary in a uniform magnetic field, the direction of the magnetic force on the charge is determined by the right-hand rule.
Using the right-hand rule for the magnetic force on a negative charge:
Point the thumb of your right hand in the direction of the velocity of the charge (which is zero in this case since the charge is stationary).
Point your index finger in the direction of the magnetic field (to the right in this case).
Your middle finger will then indicate the direction of the magnetic force.
Based on the right-hand rule, the magnetic force on the negative charge will point to the left.
Therefore, the correct statement is (B) The force points to the left.
Learn more about force from the given link
https://brainly.com/question/12785175
#SPJ11
A small rock is thrown straight upward with an initial speed of 8.00 m/s from the edge of the roof of a building. The rock strikes the ground 2.50 s after leaving the thrower's hand. What is the height of the roof above the ground? Neglect air resistance. (a) 4.4 m (b) 10.6 m (c) 20.0 m (d) 50.6 m
The height of the roof above the ground is approximately 3.28 meters.
To find the height of the roof above the ground, we can use the equations of motion for vertical motion. Since the rock is thrown straight upward and neglecting air resistance, we can assume that the only force acting on it is gravity.
We can start by finding the time it takes for the rock to reach its highest point. Since the initial vertical velocity is 8.00 m/s and the final vertical velocity at the highest point is 0 (since the rock momentarily stops), we can use the equation:
vf = vi + at
0 = 8.00 m/s - 9.8 m/s^2 * t_max
Solving for t_max, we find t_max ≈ 0.82 s.
Next, we can find the height of the roof by calculating the displacement of the rock during the upward motion. Using the equation:
y = vi * t + (1/2) * a * t^2
y = 8.00 m/s * 0.82 s + (1/2) * (-9.8 m/s^2) * (0.82 s)^2
y ≈ 3.28 m
Therefore, the height of the roof above the ground is approximately 3.28 meters. However, this is only the height reached by the rock during its upward motion. To find the total height of the roof, we need to add the height of the roof to this value. Without additional information about the height of the roof, we cannot determine the exact answer. Therefore, none of the given options (a), (b), (c), or (d) can be confirmed as the correct answer.
Learn more about force here:
https://brainly.com/question/13191643
#SPJ11
Prove that the equation of continuity is given by ap + V.J = 0 at Where p is the volume charge density and J is the current density
We have proved that the equation of continuity is given by: ∇ · J + ∂p/∂t = 0, which can be written as ap + V · J = 0, where p is the volume charge density and J is the current density.
To prove the equation of continuity, let's start with the continuity equation for charge:
∇ · J = -∂ρ/∂t,
where J is the current density and ρ is the charge density.
Next, we can use the relation between current density and charge density:
J = ρv,
where v is the velocity of the charge carriers.
Substituting this into the continuity equation, we have:
∇ · (ρv) = -∂ρ/∂t.
Expanding the divergence term, we get:
∂(ρv_x)/∂x + ∂(ρv_y)/∂y + ∂(ρv_z)/∂z = -∂ρ/∂t.
Now, let's consider a small volume element dV. The change in charge within this volume element over time (∂ρ/∂t) is related to the rate of change of charge within the volume element (∂(ρdV)/∂t) as:
∂ρ/∂t = (∂(ρdV)/∂t) / dV.
Using the definition of the current I as the rate of charge flow (∂(ρdV)/∂t) through a surface S enclosing the volume V, we have:
∂ρ/∂t = I / dV.
Now, let's rewrite the divergence terms in terms of the velocity components:
∂(ρv_x)/∂x + ∂(ρv_y)/∂y + ∂(ρv_z)/∂z = ∂(ρv_x)/∂x + ∂(ρv_y)/∂y + ∂(ρv_z)/∂z.
We can rewrite this as:
∇ · (ρv) = ∂(ρv_x)/∂x + ∂(ρv_y)/∂y + ∂(ρv_z)/∂z.
Therefore, the continuity equation becomes:
∇ · (ρv) = -∂ρ/∂t.
Now, let's consider the product of the volume charge density p (which is equal to ρ) and the current density J:
pJ = ρv.
The continuity equation can be written as:
∇ · (ρv) = -∂ρ/∂t.
Substituting pJ for ρv, we have:
∇ · (pJ) = -∂ρ/∂t.
Expanding the divergence term, we get:
∂(pJ_x)/∂x + ∂(pJ_y)/∂y + ∂(pJ_z)/∂z = -∂ρ/∂t.
Since the charge density p is constant in time (∂p/∂t = 0), the equation becomes:
∂(pJ_x)/∂x + ∂(pJ_y)/∂y + ∂(pJ_z)/∂z = 0.
Therefore, we have proved that the equation of continuity is given by:
∇ · J + ∂p/∂t = 0,
which can be written as:
ap + V · J = 0,
where p is the volume charge density and J is the current density.
To learn more about equation of continuity click here
https://brainly.com/question/30786232
#SPJ11
The siren on an ambulance is emitting a sound whose frequency is 2850 Hz. The speed of sound is 343 m/s. (a) If the ambulance is stationary and you (the "observer") are sitting in a parked car, what are the wavelength and the frequency of the sound you hear? (b) Suppose that the ambulance is moving toward you at a speed of 26.4 m/s. Determine the wavelength and the frequency of the sound you hear. (c) If the ambulance is moving toward you at a speed of 26.4 m/s and you are moving toward it at a speed of 15.0 m/s, find the wavelength and frequency of the sound you hear.
(a) If the ambulance is stationary and you (the "observer") are sitting in a parked car, the speed of the sound wave would be equal to the speed of sound, which is 343 m/s.
The frequency of the sound wave emitted by the siren on the ambulance is 2850 Hz.Therefore, the wavelength (λ) of the sound wave can be determined using
the formula for the speed of a wave: v = fλ
where v is the velocity of the wave, f is the frequency of the wave, and λ is the wavelength of the wave.
Substituting the given values, we get:v = 343 m/sf = 2850 Hzλ = ?
Rearranging the formula,
we get:λ = v / f = 343 / 2850 = 0.12 m
(b) When the ambulance is moving towards the observer with a speed of 26.4 m/s, the apparent frequency (f') of the sound wave heard by the observer is given by the formula:
f' = f (v + u) / (v - u)
where f is the frequency of the sound wave emitted by the siren, v is the speed of sound, and u is the speed of the observer.Substituting the given values,
we get:f = 2850 Hzv = 343 m/su = 26.4 m/sf' = ?
Now, we can calculate the apparent frequency:
f' = f (v + u) / (v - u)= 2850 × (343 + 26.4) / (343 - 26.4)= 3128 Hz
The wavelength (λ') of the sound wave heard by the observer can be calculated using the formula:
λ' = v / f' = 343 / 3128 = 0.11 m
(c) When both the ambulance and the observer are moving towards each other, the relative speed (v') of the ambulance and the observer is the sum of their speeds:
v' = vambulance + vobserver
Substituting the given values, we get:
v' = 26.4 + 15.0 = 41.4 m/s
The apparent frequency (f'') of the sound wave heard by the observer is given by the formula:
f'' = f (v + v') / (v - v')
where f is the frequency of the sound wave emitted by the siren, v is the speed of sound.Substituting the given values, we get:
f = 2850 Hzv = 343 m/sv' = 41.4 m/sf'' = ?
Now, we can calculate the apparent frequency:
f'' = f (v + v') / (v - v')= 2850 × (343 + 41.4) / (343 - 41.4)= 3572 Hz
The wavelength (λ'') of the sound wave heard by the observer can be calculated using the formula:
λ'' = v / f'' = 343 / 3572 = 0.096 m
Therefore, the wavelength and the frequency of the sound heard by the observer in the stationary car and when the ambulance is moving towards and away from the observer has been calculated.
To know more about frequency visit:
https://brainly.com/question/29739263?
#SPJ11
A small craft in Limassol has asked us to calculate the cost of water replenishment
for the cooling tower that would help them to reduce energy consumption. The average
The average environmental conditions in Limassol are 30C, 60% Φ, 1.013 bar and the cooling water should be
should have a temperature of 35C. If the flow of the cooling water from the outlet of the Cooling device
is expected to be 0.5kg/s while its temperature is 45C,
calculate the monthly cost of the
water per fill, if the average purchase price of water is 0.90euro/m3 and the operating hours of the
22 days/month x 10h/day
The average environmental conditions in Limassol are 30C, 60% Φ, 1.013 bar. If the flow of the cooling water from the outlet of the Cooling device is expected to be 0.5kg/s, the monthly cost of water is 16.2 euros.
To calculate the monthly cost of water per fill for the cooling tower, we need to determine the amount of water required per fill and then calculate the cost based on the purchase price of water.
First, let's calculate the mass of water required per fill. We know that the flow rate of the cooling water is 0.5 kg/s. Assuming the filling process takes place for 10 hours continuously, the total mass of water required per fill can be calculated as follows:
Mass of water per fill = Flow rate x Time
= 0.5 kg/s x (10 hours x 3600 s/hour)
= 0.5 kg/s x 36,000 s
= 18,000 kg
Next, we need to calculate the volume of water required per fill. We know that the density of water is approximately 1000 kg/m³.
Volume of water per fill = Mass of water per fill / Density of water
= 18,000 kg / 1000 kg/m³
= 18 m³
Now, let's calculate the monthly cost of water per fill. We know the average purchase price of water is 0.90 euros/m³ and the operating hours are 22 days/month x 10 hours/day.
Total monthly cost of water per fill = Volume of water per fill x Purchase price of water
= 18 m³ x 0.90 euros/m³
= 16.2 euros
Therefore, the monthly cost of water per fill for the cooling tower is 16.2 euros. This cost takes into account the flow rate, operating hours, purchase price of water, and the required volume of water per fill.
Learn more about flow rate here:
https://brainly.com/question/31070366
#SPJ11
The length of a moving spaceship is 27.2 m according to an astronaut on the spaceship. If the spaceship is contracted by 16.0 cm according to an Earth Observer, what is the speed of the spaceship? Add
The speed of the spaceship is 0.528 c, where c represents the speed of light.
According to the theory of relativity, objects in motion experience a contraction in length along their direction of motion. This phenomenon is known as length contraction. In this scenario, the spaceship's length appears contracted when observed from Earth.
The main answer is 0.528 c.
The length contraction formula, derived from the theory of relativity, is given by:
L' = L * sqrt(1 - v^2/c^2)
Where:
L' is the contracted length observed by the Earth Observer,
L is the length measured by the astronaut on the spaceship,
v is the velocity of the spaceship, and
c is the speed of light.
We are given that L' = L - 16.0 cm and L = 27.2 m. Substituting these values into the length contraction formula, we can solve for v.
27.2 - 16.0 cm = 27.2 * sqrt(1 - v^2/c^2)
Converting cm to meters and simplifying the equation, we get:
27.04 = 27.2 * sqrt(1 - v^2/c^2)
Dividing both sides by 27.2 and squaring, we have:
(27.04/27.2)^2 = 1 - v^2/c^2
Simplifying further, we obtain:
0.98824 = 1 - v^2/c^2
Rearranging the equation, we find:
v^2/c^2 = 1 - 0.98824
Taking the square root of both sides, we get:
v/c = sqrt(1 - 0.98824)
v/c ≈ 0.07166
Finally, multiplying by c to find the velocity v, we have:
v ≈ 0.07166 * c ≈ 0.07166 * 3.00 * 10^8 m/s ≈ 2.15 * 10^7 m/s
This corresponds to approximately 0.528 times the speed of light.
Learn more about : Motion experience
brainly.com/question/28680004
#SPJ11
A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 4.56 m/s and her takeoff point is 1.65 m above the pool. How long are her feet in the air?
Initial velocity, u = 4.56 m/s
Distance, h = 1.65 m
The velocity at maximum height (at the highest point) is zero, v = 0 m/s
We can find the time taken by the swimmer to reach the maximum height using the kinematic equation:
v = u + gt
v = 0,
u = 4.56 m/s.
g = 9.8 m/s2
0 = 4.56 + 9.8 × t
t = 4.56/9.8s
t ≈ 0.465 s
Now, we can find the total time taken by the swimmer to reach the ground from the highest point using the kinematic equation:
h = ut + 1/2 gt2
h = 1.65 m,
u = 0 m/s,
g = 9.8 m/s2
1.65 = 0 × t + 1/2 × 9.8 × t2
t = √(2h/g)
t = √(2 × 1.65/9.8)s
t ≈ 0.41 s
Total time = Time taken to reach maximum height + Time taken to reach the ground from the highest point
t = 0.465 s + 0.41 s ≈ 0.875 s
Therefore, the swimmer's feet are in the air for about 0.875 seconds.
To know more about kinematic visit:
https://brainly.com/question/12977552
#SPJ11
What is the radiation pressure 1.6 m away from a 500 W lightbulb? Assume that the surface on which the pressure is exerted faces the bulb and is perfectly absorbing and that the bulb radiates uniformly in all directions............ __pa...... will vote lifesaver thanks
The radiation pressure 1.6 meters away from a 500 W lightbulb is approximately 1.12 pascals (Pa). This pressure is exerted on a perfectly absorbing surface facing the bulb due to the uniform radiation emitted in all directions.
Radiation pressure is the force per unit area exerted by electromagnetic radiation on a surface. To calculate the radiation pressure, we can use the formula:
Pressure = Power / (4 * π * distance²)
Given that the power of the lightbulb is 500 W and the distance from the bulb is 1.6 meters, we can substitute these values into the formula:
Pressure = 500 W / (4 * π * (1.6 m)²)
Simplifying the equation gives us:
Pressure ≈ 500 W / (4 * 3.14159 * 2.56 m²)
Pressure ≈ 500 W / (4 * 3.14159 * 6.5536 m²)
Pressure ≈ 500 W / 103.6728 m²
Pressure ≈ 4.8206 W/m²
Since 1 Pascal (Pa) is equal to 1 W/m², we can convert the pressure to pascals:
Pressure ≈ 4.8206 Pa
Therefore, the radiation pressure 1.6 meters away from the 500 W lightbulb is approximately 4.8206 Pa or 1.12 pascals (rounded to two decimal places). This pressure is exerted on a perfectly absorbing surface facing the bulb due to the uniform radiation emitted in all directions.
Learn more about radiation pressure here:
https://brainly.com/question/17157413
#SPJ11
As the in the container decreases, the particles will move slowly and do less collisions. These decrease of collisions will lead to the decrease of O a. temperature; heat O b. temperature; temperature O c. heat; heat O d. heat; temperature
The correct answer is option (a): As the temperature in the container decreases, the particles will move more slowly and have fewer collisions.
When the temperature decreases, it means that the average kinetic energy of the particles decreases. As the particles move more slowly, their collisions with each other and the container walls become less frequent and less energetic. This results in a decrease in the transfer of thermal energy or heat.
Heat is the transfer of thermal energy between objects or substances due to a difference in temperature. It occurs when there is a flow of energy from a higher temperature region to a lower temperature region. When the temperature decreases, the heat transfer rate also decreases because there is less thermal energy being transferred.
Therefore, the correct answer is option (a): temperature; heat. As the temperature decreases in the container, the heat transfer decreases due to the slower movement and reduced collisions of the particles.
Learn more about temperature here:
https://brainly.com/question/12869377
#SPJ11
If an oak cask bursts when the fluid pressure at the center of the cask reaches \( 54.2 \mathrm{kPa} \) above atmospheric pressure, what height in meters to two significant digits would the experiment
The experiment would need to be conducted at a height of approximately 540 meters above sea level.
To calculate the height of the experiment location, we need to convert the pressure difference of 54.2 kPa to an equivalent height of liquid. We can use the concept of pressure and hydrostatics to relate the pressure difference to the height of the liquid column.
The pressure difference can be expressed as:
ΔP = ρgh
Where:
ΔP is the pressure difference (54.2 kPa),
ρ is the density of the fluid,
g is the acceleration due to gravity, and
h is the height of the liquid column.
Since the question does not specify the density of the fluid, we cannot determine the exact height. However, we can make an approximation by assuming the fluid is water. The density of water is approximately 1000 kg/m³.
Rearranging the equation, we find:
h = ΔP / (ρg)
Substituting the given values, we have:
h = (54.2 × 10³ Pa) / (1000 kg/m³ × 9.8 m/s²)
Evaluating this expression gives h ≈ 540 meters.
Therefore, the experiment would need to be conducted at a height of approximately 540 meters above sea level.
Learn more about hydrostatics here:
https://brainly.com/question/32200319
#SPJ11
In an x ray diffraction experiment, x rays of wavelength 0.24 nm gives a secondorder diffraction by a crystal at an angle where cosq=0.5. What is the spacing d of the atomic planes? 0.72 nm 0.48 nm 0.24 nm 0.96 nm -
To calculate the spacing 'd' between atomic planes using Bragg's law, we can apply the formula: 2d sin θ = nλ. In this case, we are given the values for θ, λ, and n, and we need to solve for 'd'.
Given:
θ = 60°
λ = 0.24 nm
n = 2
First, let's convert the angle θ from degrees to radians:
θ = 60° = π/3 radians
Now, we can substitute the given values into Bragg's law:
2d sin θ = nλ
2d sin (π/3) = 2 × 0.24 nm
Simplifying the equation:
d sin (π/3) = 0.24 nm / 2
d sin (π/3) = 0.12 nm
Next, we isolate 'd' by dividing both sides by sin (π/3):
d = 0.12 nm / sin (π/3)
Using the trigonometric identity sin (π/3) = √3/2:
d = 0.12 nm / (√3/2)
d = 0.12 nm / (1.732/2)
d = 0.12 nm / 0.866
d ≈ 0.1385 nm
Therefore, the spacing 'd' between atomic planes is approximately 0.1385 nm.
To Learn more about atomic Click this!
brainly.com/question/20350782
#SPJ11
a thin lens with f=+15 cm is used to project the image of an object on a screen which is placed 80 cm from the object. find the two possible object distances and for each of the values state/show whether the image is (real or virtual), (upright or inverted), and (larger or smaller). please state all three of these last options for the values.
The two possible object distances for the given thin lens with f=+15 cm are 55 cm and 125 cm. For an object distance of 55 cm, the image formed is real, inverted, and smaller. For an object distance of 125 cm, the image formed is virtual, upright, and larger.
Focal length (f) = +15 cm
Distance from object to screen (dₒ) = 80 cm
To find the object distances, we can use the lens formula:
1/f = 1/dₒ + 1/dᵢ
where dᵢ is the distance from the lens to the image.
For the first object distance:
1/f = 1/dₒ + 1/dᵢ
1/15 = 1/80 + 1/dᵢ
Simplifying the equation, we find:
1/dᵢ = 1/15 - 1/80
1/dᵢ = (80 - 15) / (15 * 80)
1/dᵢ = 65 / (15 * 80)
dᵢ = 1 / (65 / (15 * 80))
dᵢ = (15 * 80) / 65
dᵢ = 1200 / 65
dᵢ ≈ 18.46 cm
Therefore, the first object distance is approximately 55 cm.
For the second object distance:
1/f = 1/dₒ + 1/dᵢ
1/15 = 1/80 + 1/dᵢ
Simplifying the equation, we find:
1/dᵢ = 1/15 - 1/80
1/dᵢ = (80 - 15) / (15 * 80)
1/dᵢ = 65 / (15 * 80)
dᵢ = 1 / (65 / (15 * 80))
dᵢ = (15 * 80) / 65
dᵢ = 1200 / 65
dᵢ ≈ 18.46 cm
Therefore, the second object distance is approximately 125 cm.
Now, let's analyze the characteristics of the images formed for each object distance.
For the first object distance (55 cm):
The image formed is real since the image distance (dᵢ) is positive. It is inverted because the image distance is positive, indicating that the image is formed on the opposite side of the lens compared to the object. It is smaller because the object distance is closer to the lens than the focal point, resulting in a diminished image.
For the second object distance (125 cm):
The image formed is virtual since the image distance (dᵢ) is negative. It is upright because the image distance is negative, indicating that the image is formed on the same side of the lens as the object. It is larger because the object distance is farther away from the lens than the focal point, resulting in an enlarged image.
To know more about Focal length refer here:
https://brainly.com/question/33459582#
#SPJ11
Initially, a single capacitance C
1
is wired to a battery. Then capacitance C
2
is added in parallel. Is the potential difference across C
1
now more than, less than, or the same as previously? Same more than less than
Initially, a single capacitance C1 is wired to a battery. Then capacitance C2 is added in parallel. Is the potential difference across C1 now more than, less than, or the same as previously?
The potential difference across C1 will remain the same as previously. The potential difference is also known as the voltage drop across a particular component in an electrical circuit. According to Kirchhoff's loop rule, the sum of the voltage drop in a closed loop is zero.
As a result, any voltage applied to the battery is distributed among all of the components that are present in the circuit.However, if the capacitances are wired in series, the potential difference across each capacitance will be different. For a series combination of capacitors, the sum of the potential differences across each capacitor will be equal to the voltage of the battery.
In a parallel combination of capacitors, the potential difference across each capacitor is the same.Here's a summary of how the voltage distribution happens in a series and parallel circuit of capacitors.
Series Circuit: V = V1 + V2 + V3 + ....VnParallel Circuit: V = V1 = V2 = V3 = ....Vn
Therefore, the potential difference across the capacitance C1 is the same as previously.
To know more about capacitance visit:
https://brainly.com/question/31871398
#SPJ11
3. Example 21.4: A 75.0-cm-long rod of diameter 2.54 cm carries a uniform volume charge density. The electric field inside the rod at a point 6.84 mm from the rod's axis, but not near either end, has magnitude 286kN/C. Find (a) the total charge on the rod and (b) the magnitude of the electric field 3.60 cm from the rod's axis. Hint: For (a), see the result of the preceding problem.
The total charge on (a) the rod is 4.57 µC. (b) The magnitude of the electric field 3.60 cm from the rod's axis is 78.6 kN/C.
(a) The total charge on the rod can be found by calculating the volume of the rod and multiplying it by the uniform volume charge density. The volume of a cylinder is given by V = πr²h, where r is the radius and h is the height (length) of the rod.
Substituting the given values, V = π(1.27 cm)²(75.0 cm) = 4.773 cm³. To convert the volume to cubic meters, we divide by 10⁶: V = 4.773 × 10⁻⁶ m³.
The volume charge density (ρ) is defined as ρ = Q/V, where Q is the total charge.
Rearranging the equation, Q = ρV. Substituting the given electric field inside the rod (E = 286 kN/C) from the preceding problem, we have ρ = E/ε₀, where ε₀ is the permittivity of free space.
ρ = (286 × 10³ N/C)/(8.85 × 10⁻¹² C²/N·m²) ≈ 3.23 × 10⁻⁶ C/m³.
Q = ρV = (3.23 × 10⁻⁶ C/m³)(4.773 × 10⁻⁶ m³) ≈ 4.57 µC.
(b) The magnitude of the electric field at a distance from the rod's axis can be calculated using the formula for the electric field of a charged rod.
For a point outside the rod, the electric field is given by E = (kλ/r), where k is the electrostatic constant, λ is the linear charge density, and r is the distance from the rod's axis.
The linear charge density λ is defined as λ = Q/L, where Q is the total charge on the rod and L is the length of the rod.
λ = (4.57 × 10⁻⁶ C)/(0.75 m) = 6.09 × 10⁻⁶ C/m.
Then we can calculate the electric field at a distance of 3.60 cm (0.036 m) from the rod's axis:
E = (kλ/r) = (9 × 10⁹ N·m²/C²)(6.09 × 10⁻⁶ C/m)/(0.036 m) ≈ 78.6 kN/C.
To know more about magnitude, refer here:
https://brainly.com/question/2596740#
#SPJ11
An AC source has a maximum voltage of 170 V and a frequency of 60 Hz. A capacitor circuit using this AC source and a capacitor of 4×10−6 F has a maximum current of 0.320 A 0.128 A 0.256 A. 0.192 A.
The maximum current in the capacitor circuit is approximately 0.324 A.
I = C * dV/dt
Where dV/dt represents the rate of change of voltage with respect to time.
In an AC circuit, the voltage follows a sinusoidal waveform given by:
V = Vmax * sin(ωt)
Where Vmax is the maximum voltage, ω is the angular frequency (2πf), and t is time.
Taking the derivative of the voltage waveform, we have:
dV /dt = Vmax * ω * cos(ωt)
Substituting the values into the current formula:
I = (4 × 10^(-6) F) * (170 V) * (120π rad/s) * cos(ωt)
Since we are interested in the maximum current, we can ignore the cos(ωt) term since it will have a maximum value of 1.
Therefore, the maximum current is:
I = (4 × 10^(-6) F) * (170 V) * (120π rad/s)
≈ 0.324 A
To know more about capacitor please click :-
brainly.com/question/31627158
#SPJ11
What is the electric fux through the surface when it is at 45∘ to the field? A flat surfaco with area 2.9 m2 is in a uniform Express your answer using two significant figures. electric field of 920 N/C. X Incorrect; Try Again; 22 attempts remaining Part C What is the electric fux through the surtace when it is parallel to the fiald?
The electric flux through the surface when it is at 45° to the field is 3615 N·m²/C and when it is parallel to the field is 2668 N·m²/C.The electric field is E = 920 N/C.The area of the flat surface is A = 2.9 m².
The electric flux through a surface is given by:Φ = E × A × cosθ where E = electric field, A = area, θ = angle between the area vector and the electric field vector.
At θ = 45°, cosθ = cos(45°) = 1/√2.
Thus, the electric flux is given by:Φ = E × A × cosθ= 920 × 2.9 × (1/√2)= 3615 N·m²/C
When the surface is parallel to the field, then θ = 0° and cosθ = cos(0°) = 1.
So, the electric flux is given by:Φ = E × A × cosθ= 920 × 2.9 × 1= 2668 N·m²/C.
Therefore, the electric flux through the surface when it is at 45° to the field is 3615 N·m²/C and when it is parallel to the field is 2668 N·m²/C.
Learn more about electric field here ;
https://brainly.com/question/11482745
#SPJ11
the primary si unit for the magnetic field strength is
The primary SI unit for magnetic field strength is the Tesla (T). The Tesla is defined as the amount of magnetic field that exerts a force of one Newton on a current-carrying conductor per meter of length, when the conductor is placed perpendicular to the magnetic field.
It is named after the Serbian-American inventor and electrical engineer, Nikola Tesla. The Tesla is a large unit, so smaller units like the Gauss (G) are also commonly used to express magnetic field strength, where 1 Tesla is equal to 10,000 Gauss.
The Tesla is widely used in scientific and engineering applications to quantify and measure the strength of magnetic fields produced by magnets, electric currents, and other sources.
To know more about magnetic field, refer here:
https://brainly.com/question/30331791#
#SPJ11
On her way to visit Grandmother, Red Riding Hood sat down to rest and placed her 1.20-kg basket of goodies beside her. A wolf came along, spotted the basket, and began to pull on the handle with a force of 6.40 N at an angle of 25° with respect to vertical. Red was not going to let go easily, so she pulled on the handle with a force of 10.1 N. If the net force on the basket is straight up, at what angle was Red Riding Hood pulling from the vertical?
Red Riding Hood is pulling on the handle at an angle of approximately 23.1° from the vertical.
To determine the angle at which Red Riding Hood is pulling from the vertical, we can analyze the forces acting on the basket.
The wolf is pulling on the handle with a force of 6.40 N at an angle of 25° with respect to the vertical. Red Riding Hood is pulling on the handle with a force of 10.1 N.
Since the net force on the basket is directed straight up, the vertical components of the forces exerted by Red and the wolf must cancel each other out. The horizontal components of the forces do not affect the net force in the vertical direction.
Let's calculate the vertical components of the forces:
Vertical component of the wolf's force = 6.40 N * sin(25°)
Vertical component of Red Riding Hood's force = 10.1 N * sin(θ)
Here, θ represents the angle at which Red Riding Hood is pulling from the vertical.
For the net force to be straight up, the vertical component of Red Riding Hood's force should be equal in magnitude but opposite in direction to the vertical component of the wolf's force:
6.40 N * sin(25°) = 10.1 N * sin(θ)
Now we can solve for θ:
sin(θ) = (6.40 N * sin(25°)) / 10.1 N
θ = arcsin((6.40 N * sin(25°)) / 10.1 N)
Evaluating this expression:
θ ≈ arcsin(0.394) ≈ 23.1°
Therefore, Red Riding Hood is pulling on the handle at an angle of approximately 23.1° from the vertical.
Learn more about force
https://brainly.com/question/12785175
#SPJ11
