A ball of mass 10 kg is moving with a velocity of 10 m / s . It strikes another ball of mass 5 kg which is moving in the same direction with a velocity of 4 m / s . If the collision is elastic, their velocities after the collision will be, respectively

Options

A. 6 m/s, 12 m/s
B. 12 m/s, 6 m/s
C. 12 m/s, 10 m/s
D. 12 m/s, 25 m/s

Answer

A

Explanation

`v_(1)= ((m_(1)-m_(2))/(m_(1) + m_(2))) u_(1) + ((2m_(2))/(m_(1) + m_(2))) u_(2) and v_(2)= ((2m_(1))/(m_(1) + m_(2))) u_(1) + ((m_(1) -m_(2))/(m_(1) + m_(2))) u_(2)`
on putting the values `v_(1)= 6m//s and v_(2)= 12m//s`