A body of mass 4.7 kg makes an elastic collision with another body at rest and continues to move in the original direction but with 1/3 of its original speed. (a) What is the mass of the other body

Could someone me find the answer to this problem.

Suppose you have a box. which of these is not necessarily a true statement regarding the relationship between the force applied to the box, the work done on the box, and the distance the box is moved? a. if the box is not moved, no force is being applied to the box. b. if no force is applied to the box, no work is done on the box. c. if work is done on the box, then a force is applied to the box. d. if work is done on the box, then the box is moved a distance.

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?