A. The truck exerts a greater force on the car than the car exerts on the truck.
Answer:
I'm pretty sure it's the third one where velocity goes from positive to negative
Explanation:
the positive velocity is before the object hits the ground and the negative is after
Answer: 50%
Explanation: efficiency=power input/power output ×100
Eff.=300/600 ×100
Eff=½×100
Eff=50%
The answer should be copper. hope this helps :D