# 1) a water balloon is thrown toward a target at 18 m/s. If the water balloon has a mass of 0.4 kg, what is its momentum?

A) 7.2 kg • m/s
B) 18.4 kg • m/s
C) 45 kg • m/s
D) 7.2 kg • m

2) what is the momentum of a car with a mass of 2,000 kg moving at a constant velocity of 20 m/s

A) 0 kg • m/s
B) 100 kg • m/s
C) 40,000 kg • m/s
D) 0.01 kg • m/s

3) if an astronaut in space pushes off the satellite she is working on, what will happen to her if there are no other acting external forces?

A) she will eventually slow down and come to a stop
B) she will continuously speed up
C) she will periodically change direction
D) she will move in the same direction at the same speed

4) An ice skater at rest on ice catches a dance partner moving 2.5 m/s during a performance. The ice skater has a mass of 68 kg and the dance partner has a mass of 54 kg. What is the speed of the ice skater and dance partner after the collision?

A) 2.3 m/s
B) 2.0 m/s
C) 1.4 m/s
D) 1.1 m/s

5) A machine works with an efficiency of 18%. The energy input is 500 joules/second. How much useful energy will the machine generate in 15 minutes?
A) 81 kJ
B) 1.35 kJ
C) 25 kJ
D) 135 kJ

6) a lever is being used to try to lift a heavy object, but it is not working. Which of these actions would increase the output force the most?

A) decrease the input force and increase the output displacement

B) increase the input force and decrease the output displacement

C) decrease the input force and decrease the output displacement

D) increase the input force and increase the output displacement

7) a box with a weight of 50 newtons is pushed with a force of 20 newtons along an inclined plane that is 10 meters long up to the top of a ramp. What is the height of the ramp?

A) 2.5 m
B) 200 m
C) 4 m
D) 25 m

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1. anonymous you're kinda a buzz kill

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2. did u find the answers ??

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3. 1)a, 2)c ,3)d ,4)d, 5)a, 6)b, 7)c

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4. You sure do.
I am not going to do these for you.
1.momentum , P = m v
2. same
3. TOTAL momentum the same before and after. She goes one way, the sat the other
4. conservation of momentum again
5. 0.18*500 * 15 * 60
6. oh come on !
7. m g h = work in = 20 * 10, note m g = 50 N

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