Question

Two objects, A and B, each of mass 0.22 kg, are moving at 0.52 m/s directly toward each other. A completely inelastic collision occurs and both objects stop. What percentage of the total kinetic energy is changed into other forms of energy?

A. 0 percent

B. 25 percent

C. 50 percent

D. 100 percent

Answer 1

If we use conservation of momentum we can see that the objects come to a stop after they collide.

mv + mv = mv

(0.22)(0.52) + (0.22)(-0.52) = mv

0 = mv

So because they don't move after the collision that means they don't have any kinetic energy, therefore 100% of the initial kinetic energy has been changed into other forms of energy (e.g. sound and heat)