Consider the following statements A and B identify the correct choice in the give answers.
a. n a one -dimensional perfectly elastic collision between two moving bodies of equal masses, the bodies merely exhange their velocities after collision.
b.If a lighter body at rest suffers perfectly elastic collision with a very heavy body moving with a certain velocity, after collision both travel with same velocity.

Options

A. A and B are correct
B. Both A and B are wrong
C. A is correct B is wrong
D. A is wrong, B is correct

Answer

C

Explanation

When the ball A slides the quadrant of a circle, and reaches B, it covers a vertical distance h = 10cm . Its velocity at B is calculated from
`v^(2) = u^(2) + 2as`
where `u = 0, a = g = 980 cm//s^(2)` and `s = 10 cm `
`:. V^(2) = 2 xx 980 xx 10`
` :. v = sqrt( 196 xx 100) = 140 cm//s`
In an elastic collision, if B is at rest before collosion and if `m_(1) = m_(2)` then `v_(1) = 0 ` and `v_(2) = u_(1)` i.e., the first body comes to rest and the second body moves with the initial velocity of the first body. Thus in this case, the velocity of A will be zero and the velocity of B ` = 140 cm//s`