is ameasure of materials response to stress applied .it tells us the fractional change in length of object .it is the change in length divided by the original length​

One object has a mass of 1 kg and another object has a mass of 3 kg. if the speeds are the same, which of the following is true about their kinetic energy?

Ahot-air balloon is 11.0 m above the ground and rising at a speed of 7.00 m/s. a ball is thrown horizontally from the balloon basket at a speed of 9.00 m/s. ignore friction and air resistance and find the speed of the ball when it strikes the ground.

What is the efficiency of an engine that does 80 j of work and exhausts 320 j of heat while taking in 400 j of heat ? a. 10% b. 20% c. 80% d. 25%