Question

A car of 700 kg moving with a velocity of 10 m/s. A motor bike of 120 kg

also moving with same speed in the same direction lying behind 10 meter

from the car. What is there collision velocity?(

Answer 1

$u(m_1+m_2)=vm_1+vm_2,$

$u=\frac{vm_1+vm_2}{m_1+m_2}=10~\frac ms.$