A body of mass `2 kg` makes an elastic head - on collision another body at rest and continues to move in the original direction with one fourth of its original speed . The mass of the second body which collides with the first body is

Options

A. 2 kg
B. 1.2 kg
C. 3 kg
D. 1.5 kg

Answer

B

Explanation

`m_(1)= 2kg and v_(1)= ((m_(1) -m_(2))/(m_(1) + m_(2))) u_(1)= (u_(1))/(4)` (given)
By solving we get `m_(2)= 1.2 kg`