A ball with a mass of #3 kg# moving at #2 m/s# hits a still ball with a mass of #8 kg#. If the first ball stops moving, how fast is the second ball moving?

1 Answer
Apr 20, 2017

The velocity is #=0.75ms^-1#

Explanation:

We have conservation of momentum.

Let the velocities of A and B be #u_1# and #u_2# before collision

And the velocities of A and B be #v_1# and #v_2# after collision

#m_1u_1+m_2u_2=m_1v_1+m_2v_2#

#m_1=3kg#

#m_2=8kg#

#u_1=2ms^-1#

#u_2=0ms^-1#

#v_1=0ms^-1#

Therefore,

#3*2+8*0=3*0+8*v_2#

# v_2=(3*2)/(8)=3/4ms^-1#