Two objects of masses 100 g and 200 g are moving along the same line and direction with velocities of `2ms^(-1)` and `1ms^(-1)` respectively. They collide and after the collision, the first object moves with a velocity of `1.67ms^(-1)`Determine the velocity of the second object.

Explanation

Mass of the first object,
`m_(1) = 100g = (100)/(1000) kg = 0.1 kg`
Mass of the second object,
`m_(2) = 200g = (200)/(1000)kg = 0.2 kg`
Initial velocity of the first object,
`u_(2) = 2 ms^(-1)`
Initial velocity of the second object,
`u_(2) = 1ms^(-1)`
Findal velocity of the first object
`v_(1) = 1.67 ms^(-1)`
Final velocity of the second object `= v_(2)`
According to the law of conservation momentum ,
Total momentum before collision = Total momentum after collision
`rArr m_(1)u_(1) + m_(2)u_(2) = m_(1)v_(1) + m_(2)v_(2)`
`rArr 0.1 kg xx 2 ms^(-1) + 0.2 kg xx 1ms^(-1)`
`= 0.1 kg xx 1.67 ms^(-1) + 0.2 kg xx v_(2)`
`rArr 0.4 kg ms^(-1)`
`= 0.167 kg ms^(-1) + 0.2 kg v_(2)`
`rArr 0.233 kg ms^(-1) = 0.2 kg v_(2)`
`rArr v_(2) = (0.233)/(0.2) = 1.165 ms^(-1)`