Answer:
The thickness is [tex]t = 0.5615 \ cm[/tex]
Explanation:
From the question we are told that
The wavelength of the of the rader waves is [tex]\lambda = 2.92 \ cm[/tex]
The index of refraction of the polymer is [tex]n = 1.30[/tex]
The thickness is mathematically represented as
[tex]t = \frac{\lambda }{4 n }[/tex]
Substituting values
[tex]t = \frac{2.92}{4 * 1.30 }[/tex]
[tex]t = 0.5615 \ cm[/tex]
water is pumped from a stream at the rate of 90kg every 30s and sprayed into a farm at a velocity of 15m/s. Calculate the power of the pump.
Answer:
340 W
Explanation:
Power = change in energy / change in time
P = ΔKE / Δt
P = ½ mv² / Δt
P = ½ (90 kg) (15 m/s)² / (30 s)
P = 337.5 W
Rounded to 2 significant figures, the power is 340 W.
Which of the following is not true about of the use of MRI in medicine?
1) It produces no negative side-effects on the human body
2) It produces high resolution images of soft tissues
3) It is very cheap
4) It requires very strong magnetic fields
Answer:
3) False. It is expensive since it requires sophisticated equipment and very low temperatures
Explanation:
Nuclear magnetic resonance imaging measurements consist of magnetic resonance imaging to analyze tissues by the transition of the unpaired electron at carbon 13, giving information on the structure and composition of tissues. This information is processed in computers and transformed into images.
So the physical measurement is the MRN
Now we can analyze the statements in the problem
1) True by itself a magnetic measurement is non-invasive
2) True. Measuring carbon transitions has information about the soft tissue of the body
3) False. It is expensive since it requires sophisticated equipment and very low temperatures
4) Right. The applied magnetic field is high to be able to induce carbon transaction
A particle is projected at an angle 60 degrees to the horizontal with a speed of 20m/s. (i) calculate total time of flight of the particle. (i) speed of the particle at its maximum height
Answer:
Time of flight=3.5 seconds
Speed at maximum height is 0
Explanation:
Φ=60°
initial velocity=u=20m/s
Acceleration due to gravity=g=9.8 m/s^2
Total time of flight=T
Final speed=v
question 1:
T=(2 x u x sinΦ)/g
T=(2 x 20 x sin60)/9.8
T=(2 x 20 x 0.8660)/9.8
T=34.64/9.8
T=3.5 seconds
Question 2
Speed at maximum height is 0
which one of the following statements is true? A.in an elastic collision,only momentum is conserved B. in any collision,both momentum & kinetic energy are conserved C.in an inelastic collision,both momentum & kinetic energy are conserved D.in an elastic collision,only kinetic energy is conserved
Answer:
option C is correct
................
Answer:
C- in an inelastic collision, both momentum & kinetic energy are conserved
Explanation:
Took the test
The friends now feel prepared for a homework problem. Consider a cylinder initially filled with 9.30 10-4 m3 of ideal gas at atmospheric pressure. An external force is applied to slowly compress the gas at constant temperature to 1/6 of its initial volume. Calculate the work that is done. Note that atmospheric pressure is 1.013 105 Pa
Answer:
Explanation:
Initial volume of gas V₁ = 9.30 x 10⁻⁴ m³
final volume V₂ = 1 / 6 x 9.30 x 10⁻⁴
= 1.55 x 10⁻⁴ m³
Atmospheric pressure P = 1.013 x 10⁵ Pa .
temperature T .
PV = n RT
nRT = 1.013 x 10⁵ x 9.3 x 10⁻⁴
= 94.21
work done in isothermal process
= 2.303 nRT log V₁ / V₂
= 2.303 x 94.21 log 6
= 168.83 J .
You are designing an optical fiber scope for directing light into a confined area. You want to keep light within the fiber. Based on the specifications, you know that the greatest angle that the light will make with the horizontal is no greater than 25⁰. Assuming you will be using the scope in the body which has the same index of refraction of water (n = 1.33). What is the minimum index of refraction n2 required for the design to be functional?
Answer:
Explanation:
For entry of light into tube of unknown refractive index
sin ( 90 - 25 ) / sinr = μ , μ is the refractive index of the tube , r is angle of refraction in the medium of tube
r = 90 - C where C is critical angle between μ and body medium in which tube will be inserted.
sin ( 90 - 25 ) / sin( 90 - C) = μ
sin65 / cos C = μ
sinC = 1.33 / μ , where 1.33 is the refractive index of body liquid.
From these equations
sin65 / cos C = 1.33 / sinC
TanC = 1.33 / sin65
TanC = 1.33 / .9063
TanC = 1.4675
C= 56°
sinC = 1.33 / μ
μ = 1.33 / sinC
= 1.33 / sin56
= 1.33 / .829
μ = 1.6 Ans
Vocabulary Matching
The specialized equipment used to conduct research and repair
damaged equipment
Instruments
Space Station
Space Suit
Accomodations
Answer:
instruments
Explanation:
A 200.0 g block rests on a frictionless, horizontal surface. It is pressed against a horizontal spring with spring constant 4500.0 N/m (assume that the spring is massless). The block is held in position such that the spring is compressed 4.00 cm shorter than its undisturbed length. The block is suddenly released and allowed to slide away on the frictionless surface. Find the speed the block will be traveling when it leaves the spring.
Answer:
6 m/s
Explanation:
Given that :
mass of the block m = 200.0 g = 200 × 10⁻³ kg
the horizontal spring constant k = 4500.0 N/m
position of the block (distance x) = 4.00 cm = 0.04 m
To determine the speed the block will be traveling when it leaves the spring; we applying the work done on the spring as it is stretched (or compressed) with the kinetic energy.
i.e [tex]\frac{1}{2} kx^2 = \frac{1}{2} mv^2[/tex]
[tex]kx^2 = mv^2[/tex]
[tex]4500* 0.04^2 = 200*10^{-3} *v^2[/tex]
[tex]7.2 =200*10^{-3}*v^{2}[/tex]
[tex]v^{2} =\frac{7.2}{200*10^{-3}}[/tex]
[tex]v =\sqrt{\frac{7.2}{200*10^{-3}}}[/tex]
v = 6 m/s
Hence,the speed the block will be traveling when it leaves the spring is 6 m/s
What is (9x10^9)(2.6x10^-6)(1.4x10^-6) / 36
Answer:
0.00091
Explanation:
(9x10^9) (2.6x10^-6) (1.4x10^-6) / 36
(9,000,000,000) (0.0000026) (0.0000014) /36
|
23,400(0.0000014) /36
|
0.03276 /36
|
0.00091
Mr.smith and his wife were trying to move their new chair. Mr. Smith pulls with a force of 30N while Mrs.Smith pushes with a force of 25N in the same direction. What is the net force?
Answer:
55N
Explanation:
30N + 25N = 55N
Coulomb's law for the magnitude of the force FFF between two particles with charges QQQ and Q′Q′Q^\prime separated by a distance ddd is
|F|=K|QQ′|d2|F|=K|QQ′|d2,
where K=14πϵ0K=14πϵ0, and ϵ0=8.854×10−12C2/(N⋅m2)ϵ0=8.854×10−12C2/(N⋅m2) is the permittivity of free space.
Consider two point charges located on the x axis: one charge, q1q1q_1 = -15.0 nCnC , is located at x1x1x_1 = -1.660 mm ; the second charge, q2q2q_2 = 34.5 nCnC , is at the origin (x=0.0000)(x=0.0000).
What is the net force exerted by these two charges on a third charge q3q3q_3 = 47.0 nCnC placed between q1q1q_1 and q2q2q_2 at x3x3x_3 = -1.240 mm ?
Your answer may be positive or negative, depending on the direction of the force.
Answer:
Explanation:
Force between two charges of q₁ and q₂ at distance d is given by the expression
F = k q₁ q₂ / d₂
Here force between charge q₁ = - 15 x 10⁻⁹ C and q₃ = 47 x 10⁻⁹ C when distance between them d = (1.66 - 1.24 ) = .42 mm
k = 1/ 4π x 8.85 x 10⁻¹²
putting the values in the expression
F = 1/ 4π x 8.85 x 10⁻¹² x - 15 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²
= 9 x 10⁹ x - 15 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²
= 35969.4 x 10⁻³ N .
force between charge q₂ = 34.5 x 10⁻⁹ C and q₃ = 47 x 10⁻⁹ C when distance between them d = ( 1.24 - 0 ) = 1.24 mm .
putting the values in the expression
F = 1/ 4π x 8.85 x 10⁻¹² x 34.5 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²
= 9 x 10⁹ x - 34.5 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²
= 82729.6 x 10⁻³ N
Both these forces will act in the same direction towards the left (away from the origin towards - ve x axis)
Total force = 118699 x 10⁻³
= 118.7 N.
A closed container with volume of 7.20 L holds 10.9 g of liquid helium at 3.00 K and enough air to fill the rest of its volume at a pressure of 1.00 atm. The helium then evaporates and the container warms to room temperature (293 K). What is the final pressure inside the container?
Answer:
The final pressure inside the container is 107.7 atm
Explanation:
Given;
volume of the closed container = 7.20 L
mass of liquid helium in the container = 10.9 g
initial temperature of the container = 3.00 K
initial pressure of the container = 1.00 atm.
final temperature of the container = 293 K
Number of moles of He in the container = 10.9 / 4 = 2.725 moles
At 273˚K and 1 atm pressure (STP), the volume of 1 mole of a gas = 22.4 L
Volume of 2.725 moles of He at STP = 2.725 x 22.4 = 61.04 L
Volume of 2.725 moles of He at 3 K and 1 atm = (3/273) x 61.04 = 0.671 L
Thus, volume of He = 0.671 L
Volume of air in the container = 7.2 L – 0.671 L = 6.529 L
Since, the liquid helium evaporated, we only have air left in the container,
thus, final volume of the container, V₂ = 6.529 L
Initial volume of the container, V₁ = 7.20 L
Initial pressure of the in the container, P₁ = 1 atm
initial temperature of the container, T₁ = 3 K
Final temperature of the container, T₂ = 293 K
Final pressure of the container, P₂ = ?
Apply general gas law, in order to estimate P₂
[tex]\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2} \\\\P_2 = \frac{P_1V_1T_2}{T_1V_2} \\\\P_2 = \frac{1*7.2*293}{3* 6.529}\\\\P_2 = 107.7 \ atm[/tex]
Therefore, the final pressure inside the container is 107.7 atm
Now that you've done your research on the law of supply, you understand that it basically asserts that how much coffee you'd be willing to supply depends on how much money you can make for each cup.
A 50 Ohm resistance causes a current of 5 milliamps to flow through a circuit connected to a battery. What is the power in the circuit?
Answer:0.00125 watts
Explanation:
resistance=50 ohms
Current=5 milliamps
Current=5/1000 amps
Current=0.005 amps
Power=(current)^2 x (resistance)
Power=(0.005)^2 x 50
Power=0.000025 x 50
Power=0.00125 watts
Answer:
if a circuit is powered by 100v and has an overall resistance of 50 ohms 2 amps flows through the circuit
Explanation:
Why does current flow in a coil when a magnet is pushed in and out of the coil ?
Answer:
So the induced current opposes the motion that induced it (from Lenz's Law). When we pull the magnet out, the left hand end of the coil becomes a south pole (to try and hold the magnet back). Therefore the induced current must be flowing clockwise.
hope this helps u...
2. Air at a temperature of 20 ºC passes through a pipe with a constant velocity of 40 m/s. The pipe goes through a heat exchanger in which hot gases outside the pipe heat up the air to 820 ºC. It then enters a turbine with a velocity of 40 m/s and expands till the temperature falls to 620 ºC. The air stream loses 4.3 kW heat in the turbine. If the air flow rate is 2.5 kg/s, calculate (a) How much heat is transferred to the air in the heat exchanger. (b) The power output of the turbine.
Answer:
a) Q = 1436 kW
b) P ≈ 776 kW
Explanation:
Let's begin by listing out the given parameters:
T1 = 20 °C, u = 40 m/s, T2 = 820 °C, P = 4.3 kW, m = 2.5 kg/s, T3 = 510 °C, V1 = 40 m/s,
V2 = 40 m/s, V3 = 55 m/s, ṁ = 2.5 kg/s
To solve the question, we make this assumption that the size of the pipe is constant
a) No change in velocity implies that heat added is isochoric
Q = m * C * ΔT
Cv of air at 300 K(≈20 °C) = 0.718
Q = 2.5 * 0.718 * (820 − 20)
Q = 1436 kW
b) P = ṁ * Cp * ΔT + ṁ * (V2² - V3²) ÷ 2000] - Ql
V2² - V3² = 55² - 40² = 1425
ΔT = T2 - T3 = 820 - 510 = 310 °C
Cp of air at 300 K(≠20 °C) = 1.005 kJ/kgK
Ql = 4.3 kW
P = 2.5 * (1.005 * 310) + 2.5 * (1425 ÷ 2000) - 4.3
P = 778.875 + 1.78125 - 4.3 = 776.35625
P ≈ 776 kW
g 23.) [1 point] Which statement about images (formed by spherical mirrors and thin lenses) is true? Group of answer choices All of the other statements listed are false. Thin lenses always produce real images because they transmit light. A virtual image cannot be seen by the human eye. Spherical mirrors always produce real images because they reflect light. A real image cannot be formed on a screen.
Answer:
Thin lenses always produce real images because they transmit light.
Explanation:
This has been shown in Ray tracing experiments.
An astronaut is being tested in a centrifuge. The centrifuge has a radius of 11.0 m and, in starting, rotates according to θ = 0.260t2, where t is in seconds and θ is in radians. When t = 2.40 s, what are the magnitudes of the astronaut's (a) angular velocity, (b) linear velocity, (c) tangential acceleration, and (d) radial acceleration?
Answer:
a) 1.248 rad/s
b) 13.728 m/s
c) 0.52 rad/s^2
d) 17.132m/s^2
Explanation:
You have that the angles described by a astronaut is given by:
[tex]\theta=0.260t^2[/tex]
(a) To find the angular velocity of the astronaut you use the derivative og the angle respect to time:
[tex]\omega=\frac{d\theta}{dt}=\frac{d}{dt}[0.260t^2]=0.52t[/tex]
Then, you evaluate for t=2.40 s:
[tex]\omega=0.52(2.40)=1.248\frac{rad}{s}[/tex]
(b) The linear velocity is calculated by using the following formula:
[tex]v=\omega r[/tex]
r: radius if the trajectory of the astronaut = 11.0m
You replace r and w and obtain:
[tex]v=(1.248\frac{rad}{s})(11.0m)=13.728\frac{m}{s}[/tex]
(c) The tangential acceleration is:
[tex]a_T=\alpha r\\\\\alpha=\frac{\omega^2}{2\theta}=\frac{(1.248rad/s)^2}{2(0.260(2.40s)^2)}=0.52\frac{rad}{s^2}[/tex]
(d) The radial acceleration is:
[tex]a_r=\frac{v^2}{r}=\frac{(13.728m/s)^2}{11.0m}=17.132\frac{m}{s^2}[/tex]
A brick is dropped from a high scaffold.
a. How far does the brick fall during this time?
Answer:
a: after 1 seconds it will have fallen 0.2452
after 2 seconds it will have fallen 0.981
after 3 seconds it will have fallen 2.2072
after 4 seconds it will have fallen 3.924
Explanation:
the formula for acceleration due to gravity is (ignoring friction I think)
g = G*M/R^2
earths gravitational constant is about 9.807
g = 9.807*M/R^2
The average weight of a brick is 5 pounds and I'm going to say it's 10 feet off the ground.
g = 9.807*5/10^2. g = 0.4905 so every second the brick will go 0.4905 fps faster. (fps means feet per second.)
after 1 seconds it will have fallen 0.2452
after 2 seconds it will have fallen 0.981
after 3 seconds it will have fallen 2.2072
after 4 seconds it will have fallen 3.924
A large boulder falls from an underwater ledge and crashes on the floor of the ocean. A pod of dolphins is 800 meters away. Determine how long it takes for the sound of the crash to reach the dolphins.
0.5 sec
0.3 sec
2.3 sec
1.9 sec
Answer:
0.5
Explanation:
Answer:
0.539
Explanation:
A pendulum is swinging back and forth with no non-conservative forces acting on it. At the highest points of its trajectory, the kinetic energy of the pendulum bob is instantaneously equal to zero joules. At the lowest point of its trajectory, the potential energy is instantaneously equal to zero joules. Which one of the following expressions describes the kinetic and potential energies at the point mid-way between to the highest and lowest points?
A. K = 0, U = Umax
B. K = U
C. K < U
D. K > U
E. U = 0, K = Kmax
Answer:
K = U ( b )
Explanation:
The expression that describes the kinetic and potential energies at the point mid-way between to the highest and lowest points is K = U
this is because at the midpoint between the highest point and the lowest point the height is expressed as( h/2) therefore potential energy at that point is expressed as m*g*h/2 therefore the remaining energy at this point will be considered the kinetic energy which will be = m*g*h/2 as well hence at midpoint Kinetic energy = potential energy
What is the motion of the particles in this kind of wave? A hand holds the left end of a set of waves. The waves themselves make a larger set of waves in the same direction as that of the smaller waves. A label Wave motion is above the series of waves and an arrow next to the label points right. The particles will move up and down over large areas. The particles will move up and down over small areas. The particles will move side to side over small areas. The particles will move side to side over large areas.
Answer:
D
Explanation:
The particles will move side to side over large areas
Answer:
→A←Explanation:
D its incorrect in edge
a motorcycle begins at rest and accelerates uniformly at 7.9 m/s2. We want to find the time it takes the motorcycle to reach a speed of 100 km/h. Which kinetic formula would be most useful to solve for the target unknown?
Answer:
It takes the motorcycle about 12.65 seconds to reach 100mph
Explanation:
Answer:3.5 seconds
Explanation:
initial velocity=u=0
Final velocity=v=100km/h
Final velocity=v=(100x5)/18=500/18=27.8 m/s
Acceleration=a=7.9m/s^2
t=(v-u)/a
t=(27.8-0)/7.9
t=27.8/7.9
t=3.5 seconds
Who is having a hallucination?
O
A. Dominique, who doesn't know who she is anymore
O
B. Jasmine, who believes that she is a millionaire and is really a
princess
O
C. Damion, who suffers a concussion after a football game and has
memory problems
O
D. Terrance, who suffers from schizophrenia and sees faces looking
at him in the wall
Answer:
D. Terrance
Explanation:
This is because he is seeing things that aren't there.
Dominique has amnesia (useless it's just like an existential crisis)
Jasmine is having delusions? but she's not hallucinating.
Damion has I guess temporary amnesia? Maybe brain damage? but not hallucinations.
Which of the following actions would decrease the energy stored in a parallel plate capacitor when a constant potential difference is applied across the plates? (Choose from: Increasing the area of the plates; Decreasing the area of the plates; Increasing the separation between the plates; Decreasing the separation between the plates; Inserting a material with a higher dielectric constant between the plates
Answer:
increasing the separation between the plates
Explanation:
The increase in the vacuum/separation between the plates in a parallel plate capacitor connected to a constant potential difference decreases the energy stored in the capacitor. the increase in the separation of the plates of a parallel plate capacitor reduces the capacitance of the capacitor because
Q(charge) = CV V = VOLTAGE , c = capacitance
E = 1/2 eAV^2/ D ( ENERGY STORED )
where D = distance between plates, e = dielectric, A = area of capacitor , V = potential difference
Dual Nature of Light
Assignment
Active
Explaining the Nature of Light
Why do scientists believe that light is made of streams of
particles?
What are some of the benefits of learned optimism that have been found in
research?
O
A. Fewer health problems
O
O
B. All of these
C. Making more money
O
D. A lower divorce rate
Answer: fewer health problems
Explanation:
The benefits of learned optimism that have been found in research are Fewer health problems, Making more money, and a lower divorce rate. The correct option is B.
Learned optimism has been associated with numerous benefits in research, including fewer health problems, making more money, and a lower divorce rate. Optimistic people tend to have better physical and mental health, which leads to fewer health problems. Additionally, optimistic people tend to be more successful in their careers and finances, which can lead to higher income and better financial stability. Finally, optimistic people tend to have better relationships, including lower divorce rates, as they are better able to handle conflicts and maintain positive attitudes toward their partners.
In summary, learned optimism has a range of benefits for individuals, including better physical and mental health, greater success in work and education, better relationships with others, and improved resilience. These benefits make learned optimism an important skill for individuals to develop in order to lead happier, healthier, and more successful lives.
To learn about pessimism click:
https://brainly.com/question/30880008
#SPJ7
Consider a circular vertical loop-the-loop on a roller coaster. A car coasts without power around the loop. Determine the difference between the normal force exerted by the car on a passenger with a mass of mm at the top of the loop and the normal force exerted by the car on her at the bottom of the loop. Express your answer in terms of mmm and the acceleration due to gravity ggg.
Answer:
Explanation:
Let v₁ and v₂ be velocities at lowest and topmost position . Let r be the radius of the circle .
Let N₁ and N₂ be the normal reaction force .
At the top position
centripetal force = N₂ + mg ; so
N₂ + mg = m v₂² / r
At the bottom position
centripetal force = N₁ - mg ; so
N₁ - mg = m v₁² / r
subtracting these two equations
N₁ - mg - N₂ - mg = m v₁² / r - m v₂² / r
N₁ - N₂ - 2mg = 1/r (m v₁² - m v₂² )
N₁ - N₂ - 2mg = 1/r x mg x 2r ( loss of potential energy = gain of kinetic energy )
N₁ - N₂ = 2mg + 2mg
= 4 mg .
Two forces are applied on a body. One produces a force of 480-N directly forward while the other gives a 513-N force at 32.4-degrees above the forward direction .Find the magnitude and direction(relative to forward direction of the resultant force that these forces exert on the body)
Answer:
F = (913.14 , 274.87 )
|F| = 953.61 direction 16.71°
Explanation:
To calculate the resultant force you take into account both x and y component of the implied forces:
[tex]\Sigma F_x=480N+513Ncos(32.4\°)=913.14N\\\\\Sigma F_y=513sin(32.4\°)=274.87N[/tex]
Thus, the net force over the body is:
[tex]F=(913.14N)\hat{i}+(274.87N)\hat{j}[/tex]
Next, you calculate the magnitude of the force:
[tex]F=\sqrt{(913.14N)+(274.87N)^2}=953.61N[/tex]
and the direction is:
[tex]\theta=tan^{-1}(\frac{274.14N}{913.14N})=16.71\°[/tex]
Which is the correct representation of the right-hand rule for a current flowing to the right?
Answer:
The third image
Explanation:
The one with the thumb pointing to the right
Answer:
3, correct on Edge 2020
