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?

Explanation

Before collision ,

` m _(1) = m_(2) = 5 kg `
`u_(1)= 3 m//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) = 5 xx 3 + 5 xx (-3)`
Total momentum of the system after collision is
` m_(1)v + m_(2)v = (m_(1) + m_(2))v `
` = (5+ 5) v`
` n= 10v`
According to the conservation of momentum ,
Momentum before collision = Momentum after collision
` :. 0 = 10 v `
` :. v = 0 `
Hence , the velocity of the combined object after collision is zero .