A ball with a mass of #2kg# moving at #8 m/s# hits a still ball with a mass of #6 kg#. If the first ball stops moving, how fast is the second ball moving?

1 Answer
Jun 27, 2017

The velocity of the second ball is #=2.67ms^-1#

Explanation:

We have conservation of linear momentum

#m_1u_1+m_2u_2=m_1v_1+m_2v_2#

The mass #m_1=2kg#

The mass #m_2=6kg#

The velocity #u_1=8ms^-1#

The velocity #u_2=0 ms^-1#

The velocity #v_1=0ms^-1#

The velocity #v_2=?#

Therefore,

#2*8+6*0=2*0+6*v_2#

#6v_2=2*8#

#v_2=2.67ms^-1#