A ball with a mass of 2 kg is rolling at 3 m/s and elastically collides with a resting ball with a mass of 1 kg. What are the post-collision velocities of the balls?

1 Answer
May 19, 2016

v_1^'=1" m/s"
v_2^'=4 " "m/s

Explanation:

Sigma vec P_b=m_1*vec v_1+m_2*vec v_2
Sigma vec P_b=2*3+1*0
Sigma vec P_b=6 kg*m/s" Total momentum before collision"

v_1^'=(2*Sigma P_b)/(m_1+m_2)-v_1

v_1^'=(2*6)/(2+1)-3

v_1^'=12/3-3

v_1^'=4-3=1 " "m/s " velocity of "m_1 " after collision"

v_2^'=(2*Sigma P_b)/(m_1+m_2)-v_2

v_2^'=(2*6)/(2+1)-0

v_2^'=4 " "m/s" velocity of " m_2 " after collision"