Question

Two objects of masses `100g` and `200g` are moving along the same line in the same line in the same direction with velocities of `2m//s` and `1m//s`, respectively. They collide and after the collison, the first object moves at a velocity of `1.67 m//s` in the same direction. Determine the velocity of the second object.

Answer 1

Here, mass of one object, `m_(1)= 100g=(100)/(1000)kg= 1/10kg`
mass of second object, `m_(2)= 200g=(200)/(1000)kg = 1/5 kg`
Initial velocity of 1st object, `u_(1)= 2m//s`, Initial velocity of 2nd object, `u_(2)=1m//s`
Final velocity of 1st object, `v_(1)=1.67m//s`, Final velocity of 2nd object, `v_(2)=?`
According to principle of conservation of linear momentum,
`m_(1)v_(1)+m_(2)v_(2)= m_(1)u_(1)+m_(2)u_(2)` or `1/10xx1.67+1/5v_(2)=1/10xx2+1/5xx1=2/5`
or `1/5v_(2)= 2/5-(1.67)/10=7/30` or `v_(2)= 7/30xx5=7/6= 1.17m//s`