A 2 kg mass moving on a smooth frictionless surface with a velocity of 10 mshits another 2 kg mass kept at rest in an elastic collision. After collision, if they move together

Options

A. They travel with a velocity of 5 `ms^(1)` in the same direction
B. They travel with a velocity of 10 `ms^(1)` in the same direction
C. They travel with a velocity of 1`0 ms^(1)` in the
D. They travel in the opposite direction with a velocity of 5 m`s^(1) `

Answer

a

Explanation

According to lkaw of conservation of moneumteum
` m_(1) u_(1)+m_(2) u_(2)= (m_(1)+m_(2) )v`
[since objects move together after collision `v_(1)= v=_(2)=v] 2xx10 +2xx0=(2+2)v `
`v= (2xx10)/(4) =5m//s`