A ball with a mass of #2 kg# is rolling at #5 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 18, 2016

Answer:

#v_1^'=5/3 m/s#

#v_2^'=20/3 m/s#

Explanation:

#"Before Collision :"#
#m_1=2kg#
#v_1=5m/s#
#P_1=m_1*v_1" "P_1=2.5=10 kg*m/s#

#m_2=1kg#
#v_2=0#
#P_2=m_2*v_2" "P_2=1*0=0#

#"Total Momentum before Collision :"#

#Sigma P_b=P_1+P_2" "Sigma P_b=10+0 " "Sigma P_b=10 kg*m/s#

#"Post collision velocities :"#

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

#v_1^'=(2*10)/(2+1)-5#

#v_1^'=20/3-5" "v_1^'=(20-15)/3" "v_1^'=5/3 m/s#

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

#v_2=(2.10)/(2+1)-0#

#v_2^'=20/3 m/s#