2 balls have masses of 50 gm and 100 gm respectively and they are moving along the same line in the same direction with velocities of 3 m/s and 1.5 m/s respectively. They collide with each other and after the collision, the first ball moves with a velocity of 2.5 m/s. Calculate the velocity of the other ball after collision.

Explanation

The mass of first ball `= m_(1) = 50 g = 0.05 kg`, mass of the second ball `= m_(2)= 100 g = 0.1` kg Initial velocity of the first ball `= u_(1) = 3` m/s, Initial velocity of the second ball `= u_(2) = 1.5` m/s Final velocity of the first ball = `v_(1) = 2.5` m/s ,Final velocity of the second ball `= v_(2)` = ?
According to the law of conservation of momentum, total initial momentum = Total final momentum.
`m_(1)u_(1) +m_(2)u_(2) = m_(2)v_(1) +m_(2)v_(2)`
`(0.05xx3)+(0.1xx1.5)=(0.05xx2.5)+(0.1xxv_(2))`
`therefore (0.15)+(0.15)=0.125+0.1v_(2)`
`therefore 0.3=0.125+0.1v_(2)`
`therefore 0.1v_(2) =0.3-0.125 therefore v_(2) =(0.175)/(0.1)=1.75` m/s