Question

Two objects each of mass 5 kg are moving in the same straight line but in the opposite direction towards each other with some speed of 3 m/s. They stick to each other after collision. What will be the velocity of the combined object after collision?

Answer 1

Before collision, `m_(1)=m_(2)=5 kg`
`u_(1)=3m//s,u_(2)=-3 m//s`
At collision,
After collision,
Let the velocity of the combined object be v.
Total momentum before collision is
`m_(1)u_(1)+m_(2)u_(2)=5xx3+5xx(-3)=0`
Total momentum of the system after collision is
` m_(1)v+m_(2)v=(m_(1)+m_(2))v=(5+5)v=10v`