A body of mass 1 kg strikes elastically with another body at rest and continues to move in the same direction with one fourth of its initial velocity. The mass of the other bodyis-

Options

A. `0.6 kg`
B. `2.4 kg`
C. `3 kg`
D. `4 kg`

Answer

A

Explanation

COLM : `m_(1)u_(1) + m_(2)u_(2) = m_(1)v_(1) + m_(2)v_(2)`
`1 xx u + 0 = 1 xx (u)/(4) + mv_(2) rArr (3)/(4)u = mv_(a)` ….(i)
`e = -((v_(2) - v_(1))/(u_(2) - u_(1))) = - ((v_(2) - u//4)/(0 - u)) = (v_(2) - u//4)/(u)`
`v_(2) = (u)/(4) + u = (5u)/(4)` .....(ii)
(i) & (ii) `(3)/(4)u = m((5)/(4)u) rArr m = (3)/(5) = 0.6 kg`