Question

A body of mass 2 kg makes an elastic collision with another body at rest and contiues to move in the original direction with a speed equal to one thrid of its original speed. Find the mass of the second body.

Answer 1

Here, `m_(1)=2kg, u_(2)= v_(1)=(u_(1))/(3), m_(2)=?`
In a perfectly elastice collision in one dimension, `v_(1)=((m_(1)-m_(2))u_(1))/(m_(1)+m_(2))+(2m_(2)u_(2))/(m_(1)+m_(2))`
`(u_(1))/(3)=((2-m_(2)))/(2+m_(2))u_(1)+0`
`2+m_(2)=6-3m_(2)`
`4m_(2)=4, m_(2)=1kg`