Question

HELP URGENT

A 0.2 kg cue ball moving at 10 m/s hits a 0.15 kg 8 ball at rest. The cue ball continues rolling forward at 1 m/s. What is the velocity of the 8 ball?

Answer 1

We can use the principle of conservation of momentum to solve this problem. According to this principle, the total momentum of a system of objects remains constant if there are no external forces acting on the system.

Initially, only the cue ball is moving, and the 8 ball is at rest. Therefore, the initial momentum of the system is:

p_initial = m1 * v1 + m2 * v2

= 0.2 kg * 10 m/s + 0.15 kg * 0 m/s

= 2 kg m/s

After the collision, the cue ball is rolling forward at 1 m/s, and the 8 ball is moving in some direction with some velocity v_final. Therefore, the final momentum of the system is:

p_final = m1 * v1 + m2 * v_final

According to the conservation of momentum principle, p_initial = p_final. Therefore,

2 kg m/s = 0.2 kg * 1 m/s + 0.15 kg * v_final

Solving for v_final, we get:

v_final = (2 kg m/s - 0.02 kg m/s) / 0.15 kg

= 13.33 m/s

Therefore, the velocity of the 8 ball after the collision is 13.33 m/s.