You have a (copper) rod that is 702 mm at 20 C, you also have an aluminum rod that has a length of 700 mm. When the rods are the same length, what is the temperature?
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An inductor is connected to a 17 kHz oscillator that produces an rms voltage of 7.0 V . The peak current is 70 mA .What is the value of the inductance L? answer in mH.
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Could the spectral types of stars still be identified if there were no elements other than hydrogen in their atmospheres? Explain.
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The maximum speed of a child on a swing is 5.90 m/s. The child’s height above the ground is 0.790 m at the lowest point in his motion. How high above the ground is he at his highest point?
m
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A disk rotates with constant angular acceleration. The initial angular speed of the disk is 2? rad/s. After the disk rotates through 20? radians, the angular speed is 3? rad/s. (a) What is the magnitude of the angular acceleration? rad/s2 (b) How much time did it take for the disk to rotate through 20? radians? s (c) What is the tangential acceleration of a point located at a distance of 3 cm from the center of the disk? m/s2
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How much total heat transfer is necessary to lower the temperature of 0.275 kg of steam from 145.5 °C to −15.5 °C, including the energy for phase changes?
total heat transfer:
J
How much time is required for each stage of this process, assuming a constant 815.0 W rate of heat exchange? Give the times in the order that the stages occur.
t1=
t2=
t3=
t4=
t5=
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A 1,954-kg car is moving up a road with a slope (grade) of 39% while slowing down at a rate of 3.4 m/s^2. What is the direction and magnitude of the frictional force?(define positive in the forward direction, i.e., up the slope)?
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A 2,149-kg car is moving up a road with a slope (grade) of 10%
while slowing down at a rate of 3.8 m/s^2. What is the direction
and magnitude of the frictional force?
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Explain, compare, and contrast the processes by which main sequence stars generate light for low-mass stars (the proton-proton chain) and high-mass stars (the CNO cycle).
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In winter, people play hockey on Alta Lake in Whistler. However, it is not considered safe to by the Canadian Red Cross play hockey on ice until the ice is 20 cm thick. On a winter day with a temperature −10◦C, it is observed that the lake has a 1cm thick layer of ice over the entire surface.
Constants which may be of use: The thermal conductivity of ice is 2.18W/m · K. Density of ice 916.7 kg/m3 and water 1000 kg/m3. Latent heat of fusion 334x103 J/kg.
A. If the air temperature remains at −10◦C, find the rate in cm per hour at which ice is added to the layer initially. The thermal conductivity of ice is 2.18W/m · K. Note: Write cm per hour as cm/hr.
B. Find the rate in cm per hour at which ice is added to the layer as a function of the thickness x.
C. Estimate the time it takes before you can safely play hockey.
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Two 1.0 metric ton cars crash into each other. Both collide head-on, and each was travelling 27 mi/hr when the collision occurred. The wreckage is at rest after the collision. How much thermal energy was gained by the cars and road in the collision? (in case you are worried, these were driverless vehicles with no passengers inside!
Recall that a 100 W lightbulb uses up 100 Joules of energy in 1 second. If there was a way that the thermal energy from the accident described above could be completely captured and used to power such a bulb, how long would it stay lit?
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Discuss the meanings of the words "potential" and "potential difference". How are they similar and how are they different? How do these words fit in with the term "voltage"?
This question was already asked but the answer to it doesn't address all the parts of the question.
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Briefly describe what a wavefunction is. Use the term “boundary condition” in your answer. State 2 properties of wavefunctions. Give 2 examples of physical systems that would be described by wavefunctions.
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A fireworks rocket is moving at a speed of v = 45.7 m/s. The rocket suddenly breaks into two pieces of equal mass, which fly off with velocities v1 at an angle of theta1 = 30.7° and v2 at an angle of theta2 = 59.3° as shown in the drawing below.
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1) Two small, identical objects have charges of 6 μC and -3 μC. If the objects are 13 cm apart, what is the electric force the objects exert on each other? (in N)
- 7.99x10^5
- 9.59
- 4.79
- 1.20
- 3.20x10^6
2) Now imagine that the two small, identical objects with charges of 6 μC (Object A) and -3 μC (Object B) are CONDUCTORS. If the objects are brought together so they touch, then separated, what is the amount of charge on each object?
- Object A has 3.00 μC, Object B has 3.00 μC
- Object A has 6.00 μC, Object B has -3.00 μC
- Object A has 1.50 μC, Object B has 1.50 μC
- Object A has 3.00 μC, Object B has 0 μC
- Object A has -3.00 μC, Object B has 6.00 μC
3) Two small, identical conductors have charges of 6 μC and -3 μC. If the objects are brought together so they touch, then separated so they are 13 cm apart, what is the electric force the conductors exert on each other? (in N)
- 9.59
- 1.20
- 7.99x10^5
- 3.20x10^6
-4.79
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The figure shows an initially stationary block of mass m on a floor. A force of magnitude 0.500mg is then applied at upward angle ? = 20
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