A man weighing 60 kg runs along the rails with a velocity of `18 kmh^(-1)` and jumps into a car of mass 1 quintal standing on the rails. Calculate the velocity which the car will start travelling along the rails.

Explanation

Here , mass of man `m_1=60 kg`
initial velocity of man
`u_1= (18 km)/(1h)=(18 times 1000m)/(60 times 60s)= 5ms^-1`
mass of car `m_2=1` quintal =100kg
initial velocity of car `u_2=0`
After the man jumps into the car, let their common velocity be v.
Applying the principle of conservation of momentum, total momentum after jump= total momentum before jump
`(m_1+m_2)v=m_1u_1+m_2u_2`
`(60+100)v=60 times 5+100 times 0`
or `v=300/160=1.88 ms^-1`