Apparent weight/Centripetal force
GPE, KE, SPE
Hooke's Law (Spring Force)
Newton's Law of Universal Gravitation
Work and Power
100
A man is standing on a bathroom scale in an elevator. If the elevator is accelerating downwards, how would you expect the weight read on the bathroom scale to change? Increase, decrease, stay the same.
decrease
100
An 5 kg object is raised a height of 5 m, what was its gain in potential energy?
245 J
100
What variable represents the spring constant in Hooke's law? (F = -kx)
k
100
What is the equation for Newton's Universal law of gravitation?
F = G m m/r2
100
Define work and power.
The amount of energy required to move and object or change its motion, and power is the amount of energy or work done over time.
200
A mass of 15 kg is revolving in a circle with a speed of 7 m/s. If the circle has a radius of 12 m, what centripetal force must be acting on the mass?
61.25 N
200
The kinetic energy of a 2000 kg car is 45,000 J. What is the speed of the car at this moment?
6.71 m/s
200
A spring with a spring constant of 50 N/m is stretched 0.25 m, how much force is required to stretch the spring by 0.25 m?
12.5 N
200
If the distance between objects is halved (x1/2), what happens to the force of gravity between the two objects?
it increases by 4x
200
How much work is done by a man pushing a box with a constant force of 10 N, if he pushes the box 12 m?
120 J
300
A mass of 12 kg is resting on a bathroom scale sitting in an elevator as shown in the diagram to the right. If the elevator is accelerating downward at 4 m/s2, what is the apparent weight of the 12-kg mass when the elevator is accelerating downward?
69.6 N
300
A spring has a spring constant of 130 N/m. How much potential energy is stored in the spring as it is stretched 0.4 m?
10.4 J
300
How much stretch would you expect from a spring with a spring constant of 150 N/m and a force of 50 N stretching the spring?
0.33 m
300
The gravitational force between two asteroids is 500 N. What would the force be if the distance between them doubled?
125 N
300
A student who weighs 560 N climbs a flight of stairs that is 4 m high in 8 s. How much power does the student need to do this?
280 W
400
A mass of 12 kg is resting on a bathroom scale sitting in an elevator. If the elevator is accelerating upward at 4 m/s2, what is the apparent weight of the 12-kg mass when the elevator is accelerating upward?
165.6 N
400
A student compresses the spring in a pop-up toy a distance of 0.02 m. If 0.068 J of energy are stored in the toy, what is the toy's spring constant?
340 N/m
400
An unstretched spring with a spring constant of 125 N/m stretches a distance of 0.50 m when a mass is attached to the spring. The size of the mass must be of
6.37 kg
400
If the distance between two objects is tripled and the mass of one of the objects is doubled, the gravitational force between them would be
2/9 as great
400
An object has a mass of 8 kg. A 2.0-N force moves the mass at constant speed 3 m east, and then 4 m back west. How much work is done moving the block?
14 J
500
A 50-kg student riding in the coaster car is sitting on a bathroom scale when the car is in position A. The circle has a radius of 8 m, and the car’s velocity at point A is 10 m/s. What would be the reading on the bathroom scale when the student and car are at point A?
125 N
500
A student compresses the spring in a pop-up toy a distance of 0.020 m. If 0.068 J of energy are stored in the toy, what will the height of the toy be at the peak of its rise? The mass of the pop up toy is 0.008 kg.
0.86 m
500
An unstretched spring with a spring constant of 212 N/m stretches a distance of 0.65 m when a mass is attached to the spring. The size of the mass must be of
14.06 kg
500
Two bodies attract each other with a gravitational force of 90 N. What will the force of attraction be if the mass of each body is doubled, and the distance between them is tripled?
40 N
500
A motor has a power output of 1000 W. Using this power, how much time will it take the motor to raise a 50-N weight 100 m?
5 s