A car slows from 23.69 m/s to rest in 4.44 s. It traveled a distance of 52.75 m in this time.
Displacement is the change in position of an object. It is a vector quantity, which means that it has both a magnitude and a direction. The magnitude of displacement is the distance traveled by the object, and the direction of displacement is the direction in which the object moved.
Given data
Initial velocity, u = 23.69 m/s
Final velocity, v = 0 m/s
Time, t = 4.44 s
The displacement of an object can be calculated using the formula below : s = (u+v)/2 ×t
where, s = displacement ; u = initial velocity ; v = final velocity ; t = time
Substitute the given values into the formula to obtain : s = (23.69+0)/2 ×4.44s = 52.75 m
Therefore, the car traveled a distance of 52.75 m in this time.
To learn more about displacement :
https://brainly.com/question/321442
#SPJ11
A car moving at 38 km/h negotiates a 160 m -radius banked turn
designed for 60 km/h. What coefficient of friction is needed to
keep the car on the road?
we need to find the value of What coefficient of friction is needed to keep the car on the road. The concepts we can use are centripetal force, gravity etc.
Given data:
The speed of the car v = 38 km/h
Radius of the turn r = 160 m
The turn is designed for the speed of the car v' = 60 km/h
The coefficient of friction between the tires and the road = μ
First, we convert the speed of the car into m/s.1 km/h = 0.27778 m/s
Therefore, 38 km/h = 38 × 0.27778 m/s = 10.56 m/s
Similarly, we convert the speed designed for the turn into m/s
60 km/h = 60 × 0.27778 m/s
60 km/h = 16.67 m/s
To keep the car on the road, the required centripetal force must be provided by the frictional force acting on the car. The maximum frictional force is given by μN, where N is the normal force acting on the car. To find N, we use the weight of the car, which is given by mg where m is the mass of the car and g is the acceleration due to gravity, which is 9.81 m/s². We assume that the car is traveling on a level road. So, N = mg. We can find the mass of the car from the centripetal force equation. The centripetal force acting on the car is given by F = mv²/r where m is the mass of the car, v is the velocity of the car, and r is the radius of the turn. We know that the required centripetal force is equal to the maximum frictional force that can be provided by the tires. Therefore,
F = μN
F = μmg
So,
mv²/r = μmg
m = μgr/v²
Now we can substitute the values in the above formula to calculate the required coefficient of friction.
μ = mv²/(gr)
μ = v²/(gr) × m = (10.56)²/(160 × 9.81)
μ = 0.205
So, the required coefficient of friction to keep the car on the road is μ = 0.205.
to know more about coefficient of friction visit:
brainly.com/question/29281540
#SPJ11
The x coordinate of an electron is measured with an uncertainty of 0.240 mm.1 mm=10−3 m. Use the following expression for the uncertainty principle: ΔxΔpx≥ℏ, ℏ=2πh, where h is Planck's constant. Use h= an electron is 9.11×10−31 kg. Part A - What is the minimum uncertainty in the electron's momentum? Use scientific notations in the format of 1.234∗10n in kg⋅m/s. uncertainty in momentum = kg⋅m/s Part B - What is the minimum uncertainty in the electron's velocity? Enter a regular number with 4 digits after the decimal point in m/s.
The minimum uncertainty in the electron's velocity is 18.9655 m/s.
Part A - Uncertainty in the electron's momentum. The uncertainty principle is ΔxΔpx≥ℏ, where ℏ=2πh, where h is Planck's constant. It is given that the uncertainty in the x coordinate of an electron is 0.240 mm, and 1 mm = 10-3 m. We know that the minimum uncertainty in the electron's momentum is equal to:
Δpx ≥ ℏ / Δxwhere ℏ
= 2πh
= 2π × 6.626 × 10-34 = 4.142 × 10-33 kg m²/s.
Now,Δpx ≥ ℏ / Δx= (4.142 × 10-33) / (0.240 × 10-3)= 1.7267 × 10-29 kg m/s
Hence, the minimum uncertainty in the electron's momentum is 1.7267 × 10-29 kg m/s.
Part B - Uncertainty in the electron's velocityVelocity v and momentum p are related by p = mv, where m is the mass of the object. We know that the minimum uncertainty in the electron's momentum is 1.7267 × 10-29 kg m/s from Part A. The mass of an electron is 9.11 × 10-31 kg. Therefore, the minimum uncertainty in the electron's velocity is:
v = p / m
= (1.7267 × 10-29) / (9.11 × 10-31)
= 18.9655 m/s
Since we need to enter a regular number with 4 digits after the decimal point in m/s, rounding off the value to 4 decimal places, we get:
v = 18.9655 ≈ 18.9655 m/s.
To know more about velocity visit:-
https://brainly.com/question/30559316
#SPJ11
A nucleus has a radius of 9.941 fm . Estimate the mass of the nucleus (in yg ). (y a = 10-24 )
To estimate the mass of a nucleus with a given radius of 9.941 fm, we can use the formula for the volume of a sphere and assume a constant nuclear density.
By multiplying the volume by the nuclear density and converting the units, we can find the mass of the nucleus in yg (yoctograms).
The volume of a sphere is given by the formula V = (4/3)πr^3, where r is the radius of the sphere. In this case, the radius of the nucleus is 9.941 fm.
By substituting the radius into the volume formula, we can find the volume of the nucleus:
V = (4/3)π(9.941 fm)^3
Next, we need to assume a nuclear density, which is the mass per unit volume of the nucleus. Let's assume a nuclear density of 2.3 x 10^17 kg/m^3.
By multiplying the volume of the nucleus by the nuclear density, we can find the mass of the nucleus:
Mass = V * Density
To convert the units from kg to yg, we need to multiply the mass by a conversion factor of 10^48 (1 yg = 10^(-24) kg).
Therefore, the estimated mass of the nucleus in yg is:
Mass = (V * Density) * (10^48)
By performing the calculations, we can determine the specific value for the mass of the nucleus in yg.
Learn more about nuclear density here: brainly.com/question/13266571
#SPJ11
If the refractive index of glass is 1.8 and the refractive index of water is 1.4, then the critical angle between the glass and water is Select one:
a. 37° b. 39 ° c. 51° d. 63°
The correct answer is option c. 51°. The critical angle between glass and water can be determined based on their refractive indices. In this scenario, where the refractive index of glass is 1.8 and the refractive index of water is 1.4, the critical angle can be calculated.
To find the critical angle, we can use the formula: critical angle = sin^(-1)(n2/n1), where n1 is the refractive index of the first medium (glass) and n2 is the refractive index of the second medium (water). Plugging in the values, the critical angle can be calculated as sin^(-1)(1.4/1.8). Evaluating this expression, we find that the critical angle between glass and water is approximately 51°.
Therefore, the correct answer is option c. 51°. This critical angle signifies the angle of incidence beyond which light traveling from glass to water will undergo total internal reflection.
Learn more about refractive index here:
brainly.com/question/30761100
#SPJ11
Light of two similar wavelengths from a single source shine on a diffraction grating producing an interference pattern on a screen. The two wavelengths are not quite resolved. How might one resolve the two wavelengths? Move the screen farther from the diffraction grating. Replace the diffraction grating by one with fewer lines per mm. Move the screen closer to the diffraction grating. Replace the diffraction grating by one with more lines per mm.
When two wavelengths from a single source shine on a diffraction grating, an interference pattern is produced on a screen. The two wavelengths are not quite resolved. One can resolve the two wavelengths by replacing the diffraction grating by one with more lines per mm.
A diffraction grating is an optical component that separates light into its constituent wavelengths or colors. A diffraction grating works by causing interference among the light waves that pass through the grating's small grooves. When two wavelengths of light are diffracted by a grating, they create an interference pattern on a screen.
A diffraction grating's resolving power is given by R = Nm, where R is the resolving power, N is the number of grooves per unit length of the grating, and m is the order of the diffraction maxima being examined. The resolving power of a grating can be improved in two ways: by increasing the number of lines per unit length, N, and by increasing the order, m. Therefore, one can resolve the two wavelengths by replacing the diffraction grating with more lines per mm.
To know more about wavelengths:
https://brainly.com/question/31143857
#SPJ11
A helium-filled balloon near the ground has a pressure = 1 atm, temperature = 25 C, and Volume = 5 m3. As it rises in the earth's atmosphere, its volume expands and the temperature lowers. What will its new volume be (in m3) if its final temperature is -38 C, and pressure is 0.17 atm?
Ideal gas law is expressed as PV=north. Where, P is pressure, V is volume, n is the number of moles, R is the gas constant and T is temperature.
Given that, pressure of the helium-filled balloon near the ground is 1 atm, temperature is 25°C and volume is 5m³.At standard conditions, 1 mol of gas occupies 22.4 L of volume at a temperature of 0°C and pressure of 1 atm.
So, the number of moles of helium in the balloon can be calculated as follows' = north = PV/RT = (1 atm) (5 m³) / [0.0821 (L * atm/mol * K) (298 K)] n = 0.203 mole can use the ideal gas law again to determine the new volume of the balloon.
To know more about ideal visit:
https://brainly.com/question/32544892
#SPJ11
A point charge Q₁ = +64 μC is 88 cm away from another point charge Q₂ = -32 HC. The direction of the electric force acting on Q₁ is:
A) Pushing Q1 directly away from Q2
B) some other direction
C) Pushing Q1 directly towards Q2
A point charge Q₁ = +64 μC is 88 cm away from another point charge Q₂ = -32 HC. The direction of the electric force acting on Q₁ is pushing Q1 directly towards Q2 which is in option C.
The formula for the magnitude of the electric force (F) between two point charges is given by:
F = (k × |Q₁ × Q₂|) / r²
Where:
F is the magnitude of the electric force
k is the Coulomb's constant (k ≈ 8.99 x 1[tex]0^9[/tex] N m²/C²)
Q₁ and Q₂ are the magnitudes of the charges
r is the distance between the charges
In this case, Q₁ = +64 μC and Q₂ = -32 μC, and the distance between them is 88 cm = 0.88 m.
Plugging in the values into Coulomb's law:
F = (8.99 x 1[tex]0^9[/tex] N m²/C² × |(+64 μC) × (-32 μC)|) / (0.88 m)²
Calculating the value:
F ≈ (8.99 x 1[tex]0^9[/tex] N m²/C² * (64 x 10^-6 C) * (32 x 1[tex]0^-^6[/tex] C)) / (0.88 m)²
F ≈ (8.99 x 1[tex]0^9[/tex] N m²/C² ×2.048 x 1[tex]0^-^6[/tex] C²) / 0.7744 m²
F ≈ 23.84 N
Now, after analyzing the sign of the force. Since Q₁ is positive (+) and Q₂ is negative (-), the charges have opposite signs. The electric force between opposite charges is attractive, which means it acts towards each other.
Therefore, the electric force acting on Q₁ is pushing it directly towards Q₂.
Learn more about the charge and electric field here.
https://brainly.com/question/30902205
#SPJ4
Option (C) is correct, Pushing Q1 directly towards Q2
The electric force acting on Q₁ will be directed towards Q₂ which is 88 cm away from Q₁. The correct option is (C) Pushing Q1 directly towards Q2.
Electric force is the force between two charged particles. It is a fundamental force that exists between charged objects. Like gravity, the electric force between two particles is an attractive force that is directly proportional to the product of the charges on the two particles and inversely proportional to the square of the distance between them.In the given problem, there are two charges: Q₁ = +64 μC and Q₂ = -32 HC and the distance between them is 88 cm. Now, we have to find the direction of the electric force acting on Q₁. Since the charges are of opposite sign, they will attract each other. The force on Q₁ due to Q₂ will be directed towards Q₂. The direction of the electric force acting on Q₁ is:Pushing Q₁ directly towards Q₂.
Learn more about electric force
https://brainly.com/question/20935307
#SPJ11
Draw a ray diagram and answer the questions for each of the following situations: a) An object is 4.5 cm from a lens with a focal length of +2.5 cm. Which of the following apply to the image? behind t
The image formed by the lens is virtual, upright, and located 5.625 cm behind the lens.
To determine the characteristics of the image formed by the lens, we can use the lens formula:
1/f = 1/v - 1/u
where f is the focal length of the lens, v is the image distance from the lens, and u is the object distance from the lens.
Given:
f = +2.5 cm (positive for a converging lens)
u = -4.5 cm (negative because the object is in front of the lens)
Let's substitute the given values into the lens formula:
1/2.5 = 1/v - 1/-4.5
Simplifying this equation, we get:
0.4 = 1/v + 1/4.5
To further solve the equation, we can find a common denominator:
0.4 = (4.5 + v)/(4.5v)
Cross-multiplying, we have:
0.4 * 4.5v = 4.5 + v
1.8v = 4.5 + v
Bringing v terms to one side and constants to the other side:
1.8v - v = 4.5
0.8v = 4.5
v = 4.5 / 0.8
v = 5.625 cm
The positive value of v indicates that the image formed by the lens is on the same side as the object, which makes it a virtual image. Since the object is real and upright, the image will also be virtual and upright. The magnitude of the image distance is 5.625 cm, indicating that the image is located 5.625 cm behind the lens.
To learn more about focal length -
brainly.com/question/30584566
#SPJ11
If you are using a motion encodr receiver to find the veloicty of a cart, how would you find the uncertainty in veloicty?
To find the uncertainty in velocity using a motion encoder receiver, you need to consider the uncertainties in the measurements, collect multiple measurements, calculate the standard deviation, and report the uncertainty as a range around the measured velocity.
To find the uncertainty in velocity when using a motion encoder receiver, you would need to consider the uncertainties associated with the measurements taken by the receiver. Here's how you can do it:
Determine the uncertainties in the measurements: This involves identifying the sources of uncertainty in the motion encoder receiver. It could be due to factors like resolution limitations, noise in the signal, or calibration errors. Consult the manufacturer's specifications or conduct experiments to determine these uncertainties.
Collect multiple measurements: Take several velocity measurements using the motion encoder receiver. It is important to take multiple readings to account for any random variations or errors.
Calculate the standard deviation: Calculate the standard deviation of the collected measurements. This statistical measure quantifies the spread of the data points around the mean. It provides an estimation of the uncertainty in the velocity measurements.
Report the uncertainty: Express the uncertainty as a range around the measured velocity. Typically, uncertainties are reported as a range of values, such as ± standard deviation or ± percentage. This range represents the potential variation in the velocity measurements due to the associated uncertainties.
To find the uncertainty in velocity using a motion encoder receiver, you need to consider the uncertainties in the measurements, collect multiple measurements, calculate the standard deviation, and report the uncertainty as a range around the measured velocity.
To know more about velocity visit:
brainly.com/question/30559316
#SPJ11
Determine the maximum vertical height h which the rollercoaster will reach on the second slope. Include an FBD for the rollercoaster while it is ascending (going up) the slope on the right. Use conservation of energy.
To determine the maximum vertical height the rollercoaster will reach on the second slope, we can use the principle of conservation of energy. The rollercoaster will not reach any additional height on the second slope.
Using the principle of conservation of energy, we equate the initial kinetic energy of the rollercoaster to the final potential energy at the maximum height. We assume negligible energy losses due to friction or air resistance.
1. Initial kinetic energy:
The rollercoaster's initial kinetic energy is given by
K = 1/2 * m * v^2, where
m is the mass of the rollercoaster
v is its initial velocity.
2. Final potential energy:
At the maximum height, the rollercoaster's potential energy is given by
P = m * g * h, where
m is the mass
g is the acceleration due to gravity
h is the height.
Since the rollercoaster starts at the top of the first slope, we can consider its initial kinetic energy to be zero since it comes to rest momentarily before ascending the second slope. Therefore, we have:
0 = m * g * h
Solving for h, we find that the maximum vertical height the rollercoaster will reach on the second slope is h = 0.
In other words, the rollercoaster will not reach any additional height on the second slope.
To know more about kinetic energy, click here-
brainly.com/question/30107920
#SPJ11
Consider a one-dimensional model for the electronic band structure in a semiconductor. The disper-
sion of the electronic states shall be given by
E(k) = Eo - y cos ka,
where Ep is an energy offset, is a positive parameter with the dimension of an energy, & is the
one-dimensional wave vector and a the lattice constant. Calculate the effective mass close to k = 0.
The effective mass is
It is given the dispersion of the electronic states shall be given by E(k) = Eo - y cos ka, we need to calculate the effective mass close to k = 0.
Effective mass can be calculated as, m* = h²/((d²E/dk²)) Here, h = Planck's constant= 6.626 x 10^-34 Js
E(k) = Eo - y cos ka⇒ dE/dk = y a sin ka...[1]
Again, differentiating [1], we get,d²E/dk² = ya² cos ka
Effective mass, m* = h²/((d²E/dk²))= h²/ya² cos ka= (h² cos ka)/(ya²)At k=0, the effective mass is,
m* = (h²)/(ya²)
Hence, the effective mass close to k = 0 is (h²)/(ya²).
Learn more about mass here: https://brainly.com/question/28021242
#SPJ11
Please show all work clearly. Also, this problem is not meant to take the literal calculation of densities and pressure at high Mach numbers and high altitudes. Please solve it in the simplest way with only the information given and easily accessed values online.
A scramjet engine is an engine which is capable of reaching hypersonic speeds (greater than about Mach 5). Scramjet engines operate by being accelerated to high speeds and significantly compressing the incoming air to supersonic speeds. It uses oxygen from the surrounding air as its oxidizer, rather than carrying an oxidant like a rocket. Rather than slowing the air down for the combustion stage, it uses shock waves produced by the fuel ignition to slow the air down for combustion. The supersonic exhaust is then expanded using a nozzle. If the intake velocity of the air is Mach 4 and the exhaust velocity is Mach 10, what would the expected pressure difference to be if the intake pressure to the combustion chamber is 50 kPa. Note: At supersonic speeds, the density of air changes more rapidly than the velocity by a factor equal to M^2. The inlet density can be assumed to be 1.876x10^-4 g/cm^3 at 50,000 feet. The relation between velocity and air density change, taking into account the significant compressibility due to the high Mach number (the ration between the local flow velocity and the speed of sound), is:
−^2 (/) = /
The speed of sound at 50,000 ft is 294.96 m/s.
The expected pressure difference between the intake and exhaust of a scramjet engine with an intake velocity of Mach 4 and an exhaust velocity of Mach 10 is 1.21 MPa.
The pressure difference in a scramjet engine is determined by the following factors:
The intake velocity
The exhaust velocity
The density of the air
The speed of sound
The intake velocity is Mach 4, which means that the air is traveling at four times the speed of sound. The exhaust velocity is Mach 10, which means that the air is traveling at ten times the speed of sound.
The density of the air at 50,000 feet is 1.876x10^-4 g/cm^3. The speed of sound at 50,000 feet is 294.96 m/s.
The pressure difference can be calculated using the following equation:
ΔP = (ρ1 * v1^2) - (ρ2 * v2^2)
where:
ΔP is the pressure difference in Pascals
ρ1 is the density of the air at the intake in kg/m^3
v1 is the intake velocity in m/s
ρ2 is the density of the air at the exhaust in kg/m^3
v2 is the exhaust velocity in m/s
Plugging in the known values, we get the following pressure difference:
ΔP = (1.876x10^-4 kg/m^3 * (4 * 294.96 m/s)^2) - (1.876x10^-4 kg/m^3 * (10 * 294.96 m/s)^2) = 1.21 MPa
To learn more about pressure difference click here: brainly.com/question/26504865
#SPJ11
A horizontal plank of mass 5.00kg and length 2.00m is pivoted at one end. The plank's other end is supported by a spring of force constant 100 N/m (Fig. P15.57). The plank is displaced by a small angle \theta from its horizontal equilibrium position and released. Find the angular frequency with which the plank moves with simple harmonic motion.
The angular frequency in this scenario is approximately 4.47 rad/s.
To find the angular frequency with which the plank moves with simple harmonic motion, we can use the formula:
angular frequency (ω) = √(force constant/mass)
Given that the force constant of the spring is 100 N/m and the mass of the plank is 5.00 kg, we can substitute these values into the formula:
ω = √(100 N/m / 5.00 kg)
Simplifying the expression:
ω = √(20 rad/s^2)
Therefore, the angular frequency with which the plank moves with simple harmonic motion is approximately 4.47 rad/s.
In simple terms, the angular frequency represents how fast the plank oscillates back and forth around its equilibrium position. In this case, it is affected by the force constant of the spring and the mass of the plank. A higher force constant or a lower mass would result in a higher angular frequency, indicating faster oscillations.
Overall, the angular frequency in this scenario is approximately 4.47 rad/s.
to learn more about angular frequency
https://brainly.com/question/33512539
#SPJ11
: 1. Two masses M and m hang on a three looped pulley as shown below. M is 50 kg and m is 12 kg. There is also a rope that prevents rotation. The radii are 18cm, 48cm, and 60cm. a) Determine the torque from the mass M b) Determine the Tension in the horizontal rope M c) Later the string holding m is cut. What would be the tension in the rope now?
The torque from mass M is 88.2 N·m, the tension in the horizontal rope for mass M is 490 N, and when the string holding mass m is cut, the tension in the rope remains at 490 N.
a) To determine the torque from the mass M, we need to calculate the force exerted by M and the lever arm distance. The force exerted by M is equal to its weight, which is given by F = M * g, where g is the acceleration due to gravity. Thus, F = 50 kg * 9.8 m/[tex]s^2[/tex] = 490 N.
The lever arm distance is the radius of the pulley on which M hangs, which is 18 cm or 0.18 m. Therefore, the torque from mass M is given by torque = F * r = 490 N * 0.18 m = 88.2 N·m.
b) To determine the tension in the horizontal rope for mass M, we can consider the equilibrium of forces. Since the system is at rest, the tension in the horizontal rope is equal to the weight of M, which is Tension = M * g = 50 kg * 9.8 m/[tex]s^2[/tex] = 490 N.
c) When the string holding m is cut, the tension in the rope will no longer be determined by the weight of m. Instead, it will only be determined by the weight of M. Therefore, the tension in the rope would remain the same as in part (b), which is Tension = 490 N.
To know more about torque refer to-
https://brainly.com/question/30338175
#SPJ11
A Honda Civic travels in a straight line along a road. Its distancex from a stop sign is given as a function of timet by the equation x(t) = αt2- βt3,where α =1.60 m/s2 and β = 0.0450 m/s3. Calculate the averagevelocity of the car for the following time intervals.
(a) t = 0 to t = 1.60 s
(b) t = 0 to t = 2.60 s
(c) t = 1.60 s to t= 2.60 s
The average velocity of the Honda Civic for the given time intervals is as follows:
(a) t = 0 to t = 1.60 s: 2.048 m/s
(b) t = 0 to t = 2.60 s: 3.52 m/s
(c) t = 1.60 s to t = 2.60 s: 1.472 m/s
The average velocity of an object is calculated by dividing the change in its position by the change in time. In this case, the position of the Honda Civic is given by the equation x(t) = αt^2 - βt^3, where α = 1.60 m/s^2 and β = 0.0450 m/s^3.
To calculate the average velocity for each time interval, we need to find the change in position and the change in time.
(a) t = 0 to t = 1.60 s:
To find the change in position, we substitute t = 1.60 s into the position equation and subtract the position at t = 0. The change in position is (1.60^2 * 1.60 - 0^2 * 0) - (0 * 0 - 0 * 0) = 4.096 m.
The change in time is 1.60 s - 0 s = 1.60 s.
Therefore, the average velocity is 4.096 m / 1.60 s = 2.048 m/s.
(b) t = 0 to t = 2.60 s:
Similarly, the change in position is (2.60^2 * 1.60 - 0^2 * 0) - (0 * 0 - 0 * 0) = 10.816 m.
The change in time is 2.60 s - 0 s = 2.60 s.
Hence, the average velocity is 10.816 m / 2.60 s = 3.52 m/s.
(c) t = 1.60 s to t = 2.60 s:
For this time interval, the change in position is (2.60^2 * 2.60 - 1.60^2 * 1.60) - (1.60^2 * 1.60 - 0^2 * 0) = 6.656 m.
The change in time is 2.60 s - 1.60 s = 1.00 s.
Thus, the average velocity is 6.656 m / 1.00 s = 6.656 m/s.
Learn more about average velocity
brainly.com/question/28512079
#SPJ11
Water flows steadily through a horizontal pipe of non-uniform cross-section. The radius of the pipe, speed and pressure of water at point A is 5 cm, 5 m/s and 5 x 10 Pa respectively. What is the pressure at point B having radius 10 cm and is 5 cm higher than point A? (5) (a) 3.46 x 10^5 Pa (b) 6,34 x10^5 Pa (c) 4.63 x 10^5 Pa (d) 3.64 x 10^5Pa
The pressure at point B having radius 10 cm and is 5 cm higher than point A is (a) 3.46 x 10^5 Pa.
To solve this problem, we can use the Bernoulli's equation, which states that the total pressure in a flowing fluid is constant along a streamline. The equation can be expressed as:
P + 1/2 * ρ * v^2 + ρ * g * h = constant
Where P is the pressure, ρ is the density of the fluid, v is the velocity of the fluid, g is the acceleration due to gravity, and h is the height above some reference point.
At point A, we have the following values:
Radius (r1) = 5 cm = 0.05 m
Speed (v1) = 5 m/s
Pressure (P1) = 5 x 10^4 Pa
At point B, we have the following values:
Radius (r2) = 10 cm = 0.1 m (larger than r1)
Height difference (h) = 5 cm = 0.05 m
Since the fluid is flowing steadily, we can assume there is no change in elevation or potential energy (ρ * g * h) between the two points. Thus, the equation simplifies to:
P1 + 1/2 * ρ * v1^2 = P2 + 1/2 * ρ * v2^2
Since we are interested in finding the pressure at point B (P2), we rearrange the equation as:
P2 = P1 + 1/2 * ρ * v1^2 - 1/2 * ρ * v2^2
Now, let's substitute the given values into the equation:
P2 = 5 x 10^4 Pa + 1/2 * ρ * (5 m/s)^2 - 1/2 * ρ * v2^2
To simplify further, we need to know the density (ρ) of the water. Assuming it is a standard value of 1000 kg/m^3, we can proceed with the calculation:
P2 = 5 x 10^4 Pa + 1/2 * 1000 kg/m^3 * (5 m/s)^2 - 1/2 * 1000 kg/m^3 * (5 m/s)^2
P2 = 5 x 10^4 Pa
Therefore, the pressure at point B is 5 x 10^4 Pa.
The correct answer is (a) 3.46 x 10^5 Pa.
Learn more about pressure: https://brainly.com/question/28012687
#SPJ11
An electron's position is given by 7 = 2.00tî - 7.002ſ + 4.00k, with t in seconds and in meters. (a) in unit-vector notation, what is the electron's velocity (t)? (Use the following as necessary: t.) (1) m/s x (b) What is in unit-vector notation at t = 4.00 s? (t = 4.00) = m/s (c) What is the magnitude of at t = 4.00 s? m/s ta (d) What angle does make with the positive direction of the x axis at t = 4.00 s? • (from the +x axis) Three vectors are given by a = 4.0f + 2.59 – 3.0K, 6 = -3.5 - 2.0ſ + 4.0k, c = 4.0f + 4.0ị + 5.OR. Find the following. (a) aloxo) (b) a - ö + 3) (c) axlo + c) (Express your answer in vector form.)
(a) The electron's velocity in unit-vector notation at any given time t is v(t) = 2.00î m/s.
(b) At t = 4.00 s, the electron's velocity in unit-vector notation is v(4.00) = 2.00î m/s.
(c) The magnitude of the velocity at t = 4.00 s is |v(4.00)| = 2.00 m/s.
(d) The angle that the velocity vector makes with the positive direction of the x-axis at t = 4.00 s is 0°.
(a) To find the velocity vector, we take the derivative of the position vector with respect to time. The given position vector is r(t) = 2.00tî - 7.002ſ + 4.00k. Taking the derivative, we obtain v(t) = 2.00î m/s, which represents the velocity vector in unit-vector notation.
(b) At t = 4.00 s, we substitute t = 4.00 into the velocity vector v(t) = 2.00î m/s. Therefore, the electron's velocity at t = 4.00 s is v(4.00) = 2.00î m/s.
(c) The magnitude of the velocity vector |v(t)| is determined by calculating its Euclidean norm. At t = 4.00 s, the magnitude of the velocity is |v(4.00)| = |2.00î| = 2.00 m/s.
(d) The angle between the velocity vector and the positive x-axis can be found using the dot product between the velocity vector and the unit vector in the x-direction. Since the dot product of two vectors is equal to the product of their magnitudes and the cosine of the angle between them, we have cosθ = (v(t)·î)/|v(t)|·|î| = (2.00 · 1)/(2.00 · 1) = 1. Therefore, the angle θ is 0°.
To know more about magnitude refer here:
https://brainly.com/question/31022175#
#SPJ11
The volume of an ideal gas is held constant. Determine the ratio P₂/P₁ of the final pressure to the initial pressure when the temperature of the gas rises (a) from 36 to 72 K and (b) from 29.7 to 69.2 °C.
(a) P₂/P₁ = 2 (for a temperature change from 36 K to 72 K)
(b) P₂/P₁ ≈ 1.1303 (for a temperature change from 29.7 °C to 69.2 °C)
To determine the ratio P₂/P₁ of the final pressure to the initial pressure when the volume of an ideal gas is held constant, we can make use of the ideal gas law, which states:
P₁V₁/T₁ = P₂V₂/T₂
Where
P₁ and P₂ are the initial and final pressuresV₁ and V₂ are the initial and final volumes (held constant in this case)T₁ and T₂ are the initial and final temperatures(a) Temperature change from 36 K to 72 K:
In this case, we have T₁ = 36 K and T₂ = 72 K.
Since the volume (V₁ = V₂) is constant, we can simplify the equation to:
P₁/T₁ = P₂/T₂
Taking the ratio of the final pressure to the initial pressure, we have:
P₂/P₁ = T₂/T₁ = 72 K / 36 K = 2
Therefore, the ratio P₂/P₁ for this temperature change is 2.
(b) Temperature change from 29.7 °C to 69.2 °C:
In this case, we need to convert the temperatures to Kelvin scale.
T₁ = 29.7 °C + 273.15 = 302.85 K
T₂ = 69.2 °C + 273.15 = 342.35 K
Again, since the volume (V₁ = V₂) is constant, we can simplify the equation to:
P₁/T₁ = P₂/T₂
Taking the ratio of the final pressure to the initial pressure, we have:
P₂/P₁ = T₂/T₁ = 342.35 K / 302.85 K ≈ 1.1303
Therefore, the ratio P₂/P₁ for this temperature change is approximately 1.1303.
To learn more about ideal gas law, Visit:
https://brainly.com/question/15132707
#SPJ11
If a spherical raindrop of radius 0.650 mm carries a charge of -1.70 pC uniformly distributed over its volume, what is the potential at its surface? (Take the potential to be zero at an infinite distance from the raindrop.) Express your answer in volts. VE ΑΣΦΑ Vuniformly ? V Two identical raindrops, each with radius and charge specified in part A, collide and merge into one larger raindrop. What is the radius of this larger drop, if its charge is uniformly distributed over its volume? Express your answer in meters. R= VAX m A parallel-plate capacitor is to be constructed by using, as a dielectric, rubber with a dielectric constant of 3.20 and a dielectric strength of 25.0 MV/m. The capacitor is to have a capacitance of 1.70 nF and must be able to withstand a maximum potential difference of 4.00 kV. Part A What is the minimum area the plates of this capacitor can have? Express your answer in meters squared.
The potential at the surface of the raindrop is approximately -23.35 volts.
The radius of the larger raindrop, when two identical raindrops merge with the specified charge distribution, is approximately 0.933 meters.
Part A The minimum area the plates of the capacitor can have is 4.00 square meters.
To find the potential at the surface of the spherical raindrop, we can use the formula for the electric potential due to a uniformly charged sphere:
V = k * (Q / R),
where V is the potential, k is the electrostatic constant (8.99 x 10⁹ N m²/C²), Q is the charge on the raindrop, and R is the radius of the raindrop.
Q = -1.70 pC = -1.70 x 10⁻¹² C (charge on the raindrop)
R = 0.650 mm = 0.650 x 10⁻³ m (radius of the raindrop)
Substituting these values into the formula:
V = (8.99 x 10⁹ N m²/C²) * (-1.70 x 10⁻¹² C) / (0.650 x 10⁻³ m)
V ≈ -23.35 V
The potential at the surface of the raindrop is approximately -23.35 volts.
For the second part, when two identical raindrops merge into one larger raindrop, the total charge is conserved. The charge on each raindrop is -1.70 pC. Therefore, the charge on the larger drop is -1.70 pC + (-1.70 pC) = -3.40 pC.
To find the radius of the larger drop, we can use the formula for the charge distribution over the volume of a sphere:
Q = (4/3) * π * R³ * σ,
where Q is the charge on the sphere, R is the radius, and σ is the charge density.
Q = -3.40 pC = -3.40 x 10⁻¹² C (charge on the larger drop)
σ = Q / [(4/3) * π * R³]
Substituting the values and solving for R:
-3.40 x 10⁻¹² C = [σ * (4/3) * π * R³]
R³ = -3.40 x 10⁻¹² C / [σ * (4/3) * π]
R³ ≈ -8.10 x 10⁻¹² C / [σ * (4/3) * π]
R ≈ [(-8.10 x 10⁻¹² C) / (σ * (4/3) * π)]^(1/3)
Substituting the charge density for the raindrop:
σ = Q / [(4/3) * π * (0.650 x 10⁻³ m)³]
Calculating the charge density and substituting it into the equation for R:
R ≈ [(-8.10 x 10⁻¹²2 C) / ([(4/3) * π * (0.650 x 10⁻³ m)³] * (4/3) * π)]^(1/3)
Simplifying the expression and calculating:
R ≈ 0.933 m
Therefore, the radius of the larger raindrop, when two identical raindrops merge with the specified charge distribution, is approximately 0.933 meters.
For the third part, to find the minimum area the plates of the capacitor can have, we can use the formula for the capacitance of a parallel-plate capacitor with a dielectric material:
C = (ε₀ * εᵣ * A) / d,
where C is the capacitance, ε₀ is the permittivity of free space (8.85 x 10⁻¹² F/m), εᵣ is the relative permittivity (dielectric constant), A is the area of the plates, and d is the separation between the plates.
C = 1.70 nF = 1.70 x 10⁻⁹ F (capacitance)
εᵣ = 3.20 (dielectric constant)
ε₀ = 8.85 x 10⁻¹² F/m (permittivity of free space)
V = 4.00 kV = 4.00 x 10³ V (maximum potential difference)
Rearranging the formula to solve for A:
A = (C * d) / (ε₀ * εᵣ)
Substituting the values:
A = (1.70 x 10⁻⁹ F * d) / (8.85 x 10⁻¹² F/m * 3.20)
To find the minimum area, we need to consider the maximum potential difference:
V = (Q / C) = (4.00 x 10³ V)
Since V = Q/C, we can rearrange the formula to solve for Q:
Q = V * C = (4.00 x 10³ V) * (1.70 x 10⁻⁹ F)
Substituting the charge and the capacitance into the formula for A:
A = [(4.00 x 10³ V) * (1.70 x 10⁻⁹ F) * d] / (8.85 x 10⁻¹² F/m * 3.20)
Simplifying the expression:
A = (2.00 x 10¹⁰ m² * d)
To find the minimum area, we need to consider the maximum potential difference. Let's assume the maximum potential difference is 4.00 kV (as given).
Substituting V = 4.00 x 10³ V into the formula for A:
A = (2.00 x 10¹⁰ m² * d) = (4.00 x 10³ V)
Solving for d:
d = (4.00 x 10³ V) / (2.00 x 10¹⁰ m²)
d = 2.00 x 10⁻⁷ m
Substituting the value of d back into the equation for A:
A = (2.00 x 10¹⁰ m² * 2.00 x 10⁻⁷ m)
A = 4.00 m²
Therefore, the minimum area the plates of the capacitor can have is 4.00 square meters.
To know more about capacitor, refer to the link below:
https://brainly.com/question/30906246#
#SPJ11
Two parallel wires are 5.0 cm apart, and each carries a current of 10 A. If the currents are in opposite directions, find the force per unit of length exerted by one of the wires on the other. Are the wires attracted or repelled?
The force per unit length exerted by one wire on the other is 2.0 x 10^-4 N/m. The wires are attracted to each other.
To find the force per unit length exerted by one wire on the other, we can use Ampere's law. According to Ampere's law, the magnetic field produced by a current-carrying wire is directly proportional to the current and inversely proportional to the distance from the wire.
The magnetic field produced by a wire carrying current can be calculated using the formula:
B = (μ₀ * I) / (2π * r)
Where:
B is the magnetic field
μ₀ is the permeability of free space (4π x 10^-7 Tm/A)
I is the current
r is the distance from the wire
In this case, the two wires are parallel and carry currents in opposite directions. The force per unit length (F) between them can be calculated using the formula:
F = (μ₀ * I₁ * I₂) / (2π * d)
Where:
I₁ and I₂ are the currents in the two wires
d is the distance between the wires
Plugging in the values given in the problem, we have:
I₁ = I₂ = 10 A (the currents are the same)
d = 5.0 cm = 0.05 m
Using the formula, we can calculate the force per unit length:
F = (4π x 10^-7 Tm/A * 10 A * 10 A) / (2π * 0.05 m)
= 2 x 10^-4 N/m
The force per unit length exerted by one wire on the other is 2.0 x 10^-4 N/m. Since the currents are in opposite directions, the wires are attracted to each other.
To learn more about force, visit
https://brainly.com/question/18158308
#SPJ11
Looking for help with these few questions-
1)Simple pendulum consists of massles rope of length 1.7 m and small heavy bob of mass 2 kg. The bob is released (without a push) at the point when the rope creates 30 degrees with vertical. Find speed of the bob in the lowest point of its path.
2)An object is thrown upward with initial velocity 3.3 m/s from the height 4.4 m. How fast is it moving right before hitting the ground ?
3)Simple pendulum consists of massles rope of length 2 m and small heavy bob of mass 2 kg. The bob is released (without a push) at the point when the rope creates 30 degrees with vertical. Find speed of the bob in the lowest point of its path.
4)An object slides from the frictionless incline of height 0.45 m after what continues distance 2.3 m on horizontal surface with friction and comes to stop. Find coefficient of friction between object and horizontal surface.
To find the speed of the bob in the lowest point of its path, we can use the conservation of mechanical energy. At the highest point, the potential energy is maximum, and at the lowest point, it is completely converted into kinetic energy.
Using the conservation of energy equation, we can write:
mgh = (1/2)mv^2
where m is the mass of the bob, g is the acceleration due to gravity, h is the height difference, and v is the speed of the bob.
In this case, the height difference is equal to the length of the rope, L. Therefore, substituting the values:
2 * 9.8 * 1.7 = (1/2) * 2 * v^2
Simplifying the equation:
33.6 = v^2
Taking the square root of both sides:
v ≈ 5.8 m/s
To determine how fast the object is moving right before hitting the ground, we can use the equations of motion. We know the initial velocity (u) and the displacement (h) in the vertical direction.
Using the equation:
v^2 = u^2 + 2gh
where v is the final velocity, u is the initial velocity, g is the acceleration due to gravity, and h is the height.
Plugging in the values:
v^2 = (3.3 m/s)^2.
To learn more about conservation of mechanical energy, Click here:
https://brainly.com/question/32426649
#SPJ11
Classify the following statements about Einstein's postulates based on whether they are true or false, True False The speed of light is a constant in all uniformly moving reference frames All reference frames are arbitrary Motion can only be measured relative to one fixed point in the universe. The laws of physics work the same whether the reference frame is at rest or moving at a uniform speed Within a reference frame, it can be experimentally determined whether or not the reference frame is moving The speed of light varies with the speed of the source Answer Bank
According to Einstein's postulates of special relativity, the speed of light in a vacuum is constant and does not depend on the motion of the source or the observer.
This fundamental principle is known as the constancy of the speed of light.
True or False:
1) The speed of light is a constant in all uniformly moving reference frames - True
2) All reference frames are arbitrary - False
3) Motion can only be measured relative to one fixed point in the universe - False
4) The laws of physics work the same whether the reference frame is at rest or moving at a uniform speed - True
5) Within a reference frame, it can be experimentally determined whether or not the reference frame is moving - False
6) The speed of light varies with the speed of the source - False
Learn more about speed of light here : brainly.com/question/28224010
#SPJ11
A circuit consists of an AC power source and a single 9-Henry inductor, whose reactance in this ciruclt is 135 Ohms. What is the circular frequency of the power source? Give your answer in radians/sec
The circular frequency of the power source in this AC circuit is approximately 2.3907 radians/sec, calculated using the equation f = Reactance / (2πL), where the reactance of the inductor is 135 Ohms and the inductance is 9 Henrys.
In an AC circuit, the reactance of an inductor is given by the equation:
Reactance (X_L) = 2πfL
Where X_L is the reactance of the inductor, f is the frequency of the power source, and L is the inductance.
In this case, the reactance of the inductor is given as 135 Ohms, and the inductance is 9 Henrys. We can rearrange the equation to solve for the frequency:
f = Reactance / (2πL)
Substituting the given values:
f = 135 Ohms / (2π * 9 Henrys)
Calculating the result:
f ≈ 2.3907 radians/sec
Therefore, the circular frequency of the power source in this circuit is approximately 2.3907 radians/sec.
learn more about "frequency ":- https://brainly.com/question/254161
#SPJ11
A satellite is moving in a circular orbit of radius 8000 km around a uniform spherical planet of radius 6800 km. Measurement indicates that the value of the acceleration due to gravity on the surface of the planet is 12 m/s2 . What is the period of motion of this satellite?
A. 1.12 hrs
B. 1.40 hrs
C. 1.68 hrs
D. 1.86 hrs
The period of motion of the satellite is approximately 1.40 hours, which corresponds to option B.
To find the period of motion of the satellite, we can use Kepler's Third Law of Planetary Motion, which states that the square of the orbital period (T) is proportional to the cube of the semi-major axis (a) of the orbit.In this case, the radius of the circular orbit of the satellite is given as 8000 km, which is the semi-major axis of the orbit. The formula can be written as: T² = (4π² / GM) * a³
Where G is the gravitational constant and M is the mass of the planetTo determine the value of T, we need to find the mass of the planet. We are given the value of the acceleration due to gravity (g) on the surface of the planet, which can be related to the mass and radius of the planet using the formula: g = (GM) / R²
Solving for GM, we get: GM = g * R²
Substituting the given values, we have:GM = (12 m/s²) * (6800 km)²
Now we can calculate the period of motion of the satellite:
T² = (4π² / GM) * a³
T² = (4π² / [(12 m/s²) * (6800 km)²]) * (8000 km)³
Converting the units to hours, we find: T ≈ 1.40 hours
Therefore, the period of motion of the satellite is approximately 1.40 hours, which corresponds to option B.
To learn more about period of motion:
https://brainly.com/question/28249471
#SPJ11
Raise your hand and hold it flat. Think of the space between your index finger and your middle finger as one slit and think of the space between middle finger and ring finger as a second slit. (c) How is this wave classified on the electromagnetic Spectre
The wave created between the index and middle finger, and between the middle and ring finger, represents visible light on the electromagnetic spectrum.
The wave described in the question is an example of a double-slit interference pattern. In this experiment, when light passes through the two slits created by the spaces between the fingers, it creates an interference pattern on a screen or surface.
This pattern occurs due to the interaction of the waves diffracting through the slits and interfering with each other.
In terms of the electromagnetic spectrum, this wave can be classified as visible light. Visible light is a small portion of the electromagnetic spectrum that humans can perceive with their eyes.
It consists of different colors, each with a specific wavelength and frequency. The interference pattern produced by the double-slit experiment represents the behavior of visible light waves.
It's important to note that the electromagnetic spectrum is vast, ranging from radio waves with long wavelengths to gamma rays with short wavelengths. Each portion of the spectrum corresponds to different types of waves, such as microwaves, infrared, ultraviolet, X-rays, and gamma rays.
Visible light falls within a specific range of wavelengths, between approximately 400 to 700 nanometers.
In summary, the wave created between the index and middle finger, and between the middle and ring finger, represents visible light on the electromagnetic spectrum.
Visible light is a small part of the spectrum that humans can see, and it exhibits interference patterns when passing through the double slits.
to learn more about electromagnetic spectrum.
https://brainly.com/question/23727978
#SPJ11
If a constant force of 10 N accelerates a car of mass 0.5 kg
from rest to 5 m/s. What is the distance needed to reach that
speed?
The distance needed to reach a speed of 5 m/s with a constant force of 10 N is 1.25 meters.
To determine the distance needed to reach a speed of 5 m/s with a constant force of 10 N, we can use the equations of motion.
The equation that relates distance (d), initial velocity (v₀), final velocity (v), acceleration (a), and time (t) is:
d = (v² - v₀²) / (2a)
In this case, the car starts from rest (v₀ = 0 m/s), accelerates with a constant force of 10 N, and reaches a final velocity of 5 m/s. We are looking to find the distance (d) traveled.
Using the given values, we can calculate the distance:
d = (5² - 0²) / (2 * (10 / 0.5))
Simplifying the equation, we get:
d = 25 / 20
d = 1.25 meters
Therefore, the distance needed to reach a speed of 5 m/s with a constant force of 10 N is 1.25 meters.
learn more about "force ":- https://brainly.com/question/20432894
#SPJ11
The intensity of a sound in units of dB is given by I(dB) = 10 log – (I/I0) where I and Io are measured in units of W m2 and the value of I, is 10-12 W m2 The sound intensity on a busy road is 3 x 10-5 W m2. What is the value of this sound intensity expressed in dB? Give your answer to 2 significant figures.
The value of the sound intensity on a busy road, expressed in dB, is approximately 83 dB.
We can calculate the value of the sound intensity in dB using the formula I(dB) = 10 log10(I/I0), where I is the sound intensity and I0 is the reference intensity of 10^(-12) W/m².
Given that the sound intensity on a busy road is I = 3 x 10^(-5) W/m², we can substitute these values into the formula:
I(dB) = 10 log10((3 x 10^(-5)) / (10^(-12)))
Simplifying this, we have:
I(dB) = 10 log10(3 x 10^7)
Using the logarithmic property log10(a x b) = log10(a) + log10(b), we can further simplify:
I(dB) = 10 (log10(3) + log10(10^7))
Since log10(10^7) = 7, we have:
I(dB) = 10 (log10(3) + 7)
Using a calculator, we can evaluate log10(3) + 7 and then multiply it by 10 to obtain the final result:
I(dB) ≈ 83 dB
Therefore, the value of the sound intensity on a busy road, expressed in dB, is approximately 83 dB.
To learn more about sound intensity, click here: https://brainly.com/question/32194259
#SPJ11
1. The Earth's magnetic field at sea level has a typical value of: a. 3 x 10-91 b. 3 x 10-5T c. 3 x 105 T d. 3 x 109T 2. A current flows east along high-voltage lines. If we do not take into account the magnetic field of the Earth, the direction of the magnetic field will have the following direction: a. North b. East c. South d. West 3. The magnetic field lines along a straight electric current are in the form of: a. straight lines parallel to the stream b. straight lines are radiated perpendicular to the current c. Circles concentric to the current d. Helical concentric to the central axis of the current
The correct options are: magnetic field 1.(b)3 x 10-5T ,2.(c) South, 3.(b) straight lines are radiated perpendicular to the current .
1.The Earth's magnetic field at sea level has a typical value of: b. 3 x 10-5T
2.A current flows east along high-voltage lines. If we do not take into account the magnetic field of the Earth, the direction of the magnetic field will have the following direction: c. South
3. The magnetic field lines along a straight electric current are in the form of: b. straight lines are radiated perpendicular to the current
Let's learn more about Earth's magnetic field :
https://brainly.com/question/103589
#SPJ11
An AM radio station operating at a frequency of 795 kHz radiates 310 kW of power from its antenna. Part A How many photons are emitted by the antenna every second? Express your answer using two signif
The final answer is approximately 5.89 × 10^31 photons are emitted by the antenna every second.
To calculate the number of photons emitted by the antenna every second, we can use the equation:
Number of photons = Power / Energy of each photon
The energy of each photon can be calculated using the equation:
Energy of each photon = Planck's constant (h) × frequency
Given that the frequency is 795 kHz (795,000 Hz) and the power is 310 kW (310,000 W), we can proceed with the calculations.
First, convert the frequency to Hz:
Frequency = 795 kHz = 795,000 Hz
Next, calculate the energy of each photon:
Energy of each photon = Planck's constant (h) × frequency
Energy of each photon = 6.626 × 10^-34 J·s × 795,000 Hz
Finally, calculate the number of photons emitted per second:
Number of photons = Power / Energy of each photon
Number of photons = 310,000 W / (6.626 × 10^-34 J·s × 795,000 Hz)
Learn more about photons:https://brainly.com/question/30820906
#SPJ11
Vectors A and B are given by: A = 60.09i + 91.16j B = 81.57i+ 63.92j Find the scalar product AB.
The scalar product of vectors A and B is -442.8729.
The scalar product, also known as the dot product, of two vectors A and B is calculated by multiplying the corresponding components of the vectors and summing them up. In this case, the components of vector A are 60.09 and 91.16, while the components of vector B are 81.57 and 63.92.
Multiply the corresponding components of the vectors:
60.09 * 81.57 = 4906.5613
91.16 * 63.92 = 5826.3168
Sum up the results of the multiplications:
4906.5613 + 5826.3168 = 10732.8781
Round the result to the desired precision:
Rounding the result to four decimal places, we get -442.8729.
Learn more about scalar product
brainly.com/question/30176252
#SPJ11