The kinetic energy of a rolling billiard ball is given by {\rm{KE}} = 1/2\,mv^2 . Suppose a 0.17-{\rm kg} billiard ball is rolling down a pool table with an initial speed of 4.5 m/s. As it travels, it loses some of its energy as heat. The ball slows down to 4.0 m/s and then collides straight-on with a second billiard ball of equal mass. The first billiard ball completely stops and the second one rolls away with a velocity of 4.0 m/s. Assume the first billiard ball is the system

Question

How do I calculate work for a problem like this? I know how to calculate kinetic energy, but this question is asking for q and w.

Could someone please explain the steps it would take to answer a problem like this? Thank you.

Answer 1

According to the Work-Energy Theorem,
Work = Ek(final) - Ek(initilal)

Ek(initilal) = (1/2)mv^2 = (1/2)(0.17kg)(4.5 m/s)^2

Ek(final) = (1/2)mv^2 = (1/2)(0.17kg)(4.0 m/s)^2

Work = ?__________

NOTE: This looks like a Physics question.

Answer 2

-1.4 J