Two identical balls collide head on. The initial velocity of one is `0.75 ms^(-1)` , while that of the other is `-0.43 ms^(-1)`. If the collision is perfectly elastic, then their respective final velocities are

Options

A. `0.75 ms^(-1), -0.43 ms^(-1)`
B. `0.43 ms^(-1), 0.75 ms^(-1)`
C. `-0.75 ms^(-1), 0.43 ms^(-1)`
D. `0.43 ms^(-1), 0.75 ms^(-1)`

Answer

`(2)`

Explanation

` vec v_(1) = (m_(1) - m_(2)/m_(1) + m_(2)) vec u_(1) + (2m_(2)/m_(1) +m_(2))vec u_(2)`
`vec v_(2) = (2m_(1)/m_(1) + m_(2))vec u_(1) + (m_(2) - m_(1)/m_(1) + m_(2) ) vec u_(2)`