A body of mass 5 kg moving with a velocity of `6 m s^(-1)` collide with another body of mass 2 kg which is at rest. Afterwards they move in the same direction as before. If the velocity of the body of mass 2 kg `10 ms^(-1)` , find the velocity and kinetic energy to the body of mass 5 kg.

Explanation

Given `m_1=5 kg , u_(1)=6 ms^(-1)`
`m_(2)=2 kg , u_(2)=0`
` v_(2)=10 ms^(-1), v_(1)= ? KE1 =?`
Applying `m_(1)u_(1)+ m_(2)u_(2)= m_(1)v_(1)+m_(2)v_(2)` we get
`5 xx 6 +2xx0 = 5v_(1)+2 xx 10`
i.e `5v_(1)=30-20 = 10`
or `v_(1)= 10/5 = 2 ms^(-1)` in the direction of `vec v_(2)`
kinetic energy of `m_(1)= 1/2 m_(1)v_(1)^(2)= 1/2 xx 5 xx2 xx 2`
`K.E= 10 J`