A piece of fruit falls straight down. As it falls, the: A. g…

A piece of fruit falls straight down. As it falls, the: A. gravitational force does positive work on it and the   gravitational potential energy increases. B. gravitational force does positive work on it and the   gravitational potential energy decreases. C. gravitational force does negative work on it and the   gravitational potential energy increases. D. gravitational force does negative work on it and the   gravitational potential energy decreases.

You are testing a new car using crash test dummies. Consider…

You are testing a new car using crash test dummies. Consider two ways to slow the car from 90 km/h (56 mi/h) to a complete stop: (i)  You let the car slam into a wall, bringing it to a sudden stop. (ii)  You let the car plow into a giant tub of gelatin so that it comes   to a gradual halt. In which case is there a greater impulse of the net force on the car? A. In case (i). B. In case (ii). C. The impulse is the same in both cases. D. The answer depends on how rigid the front of the car is.

Rank the following objects in order of the magnitude of the…

Rank the following objects in order of the magnitude of the momentum of the object, from largest to smallest.   A. Mass = 2.0 kg, kinetic energy = 2.0 J B. Mass = 1.0 kg, kinetic energy = 2.0 J C. Mass = 2.0 kg, kinetic energy = 4.0 J D. Mass = 4.0 kg, kinetic energy = 4.0 J

Rank the following objects in order of their kinetic energy,…

Rank the following objects in order of their kinetic energy, from largest to smallest: A.  A 2.00-kg object moving at 1.00 m/s B.  A 1.00-kg object moving at 2.00 m/s C.  A 4.00-kg object that was initially at rest, then had 8.00 J of   total work done on it D.  A 4.00-kg object that was initially moving at 2.00 m/s, then   had –8.00 J of total work done on it

A ball (mass 0.40 kg) is initially moving to the left at 30…

A ball (mass 0.40 kg) is initially moving to the left at 30 m/s. After hitting the wall, the ball is moving to the right at 20 m/s. What is the impulse of the net force on the ball during its collision with the wall? A. 20 kg • m/s to the right B. 20 kg • m/s to the left C. 4.0 kg • m/s to the right D. 4.0 kg • m/s to the left

A block is released from rest on a frictionless incline as s…

A block is released from rest on a frictionless incline as shown. When the moving block is in contact with the spring and compressing it, what is happening to the gravitational potential energy Ugrav and the elastic potential energy Uel? A. Ugrav and Uel are both increasing. B. Ugrav and Uel are both decreasing. C. Ugrav is increasing; Uel is decreasing. D. Ugrav is decreasing; Uel is increasing.