A 1 kg ball moving at 12 ms -1 collides with a 2 kg ball moving in opposite direction at 24 ms -1 . If the coefficient of restitution is (2/3), the their velocities after the collision are

Question

A 1 kg ball moving at 12 ms -1 collides with a 2 kg ball moving in opposite direction at 24 ms -1 . If the coefficient of restitution is (2/3), the their velocities after the collision are (A) -4 ms -1,-28 ms -1 (B) -28 ms -1,-4 ms -1 (C) 4 ms -1, 28 ms -1 (D) 28 ms -1, 4 ms -1

Tardigrade Admin · Accepted Answer

m 1=1 kg , u 1=12 m s -1 m 2=3 kg , u 2=-24 m s -1 e =( v 2- v 1/ u 1- u 2) (2/3)=( v 2- v 1/36) v 2- v 1=(36 × 2/3) v 2- v 1=24 ... (1) m 1 u 1+ m 2 u 2= m 1 v 1+ m 2 v 2 1 × 12+2 ×(-24)= v 1+2 v 2 12-48= v 1+2 v 2 v 1+2 v 2=-36 (- v 1+ v 2=24/3 v 2=-12) v 2=-4 m s -1 [from equation (1)] -4- v 1=24 -4-24= v 1 v 1=-28 m s -1

Q. A $1 k g$ ball moving at $12 m s^{- 1}$ collides with a $2 k g$ ball moving in opposite direction at $24 m s^{- 1} .$ If the coefficient of restitution is $\frac{2}{3}$ , the their velocities after the collision are

$- 4 m s^{- 1}, - 28 m s^{- 1}$

$- 28 m s^{- 1}, - 4 m s^{- 1}$

$4 m s^{- 1}, 28 m s^{- 1}$

$28 m s^{- 1}, 4 m s^{- 1}$

Q. A 1kg ball moving at 12ms−1 collides with a 2kg ball moving in opposite direction at 24ms−1. If the coefficient of restitution is 32​, the their velocities after the collision are

−4ms−1,−28ms−1

−28ms−1,−4ms−1

4ms−1,28ms−1

28ms−1,4ms−1

Q. A $1 k g$ ball moving at $12 m s^{- 1}$ collides with a $2 k g$ ball moving in opposite direction at $24 m s^{- 1} .$ If the coefficient of restitution is $\frac{2}{3}$ , the their velocities after the collision are

$- 4 m s^{- 1}, - 28 m s^{- 1}$

$- 28 m s^{- 1}, - 4 m s^{- 1}$

$4 m s^{- 1}, 28 m s^{- 1}$

$28 m s^{- 1}, 4 m s^{- 1}$