Question

a body of mass 2 kg moving with uniform velocity of 40 metre per second collides with another body to body move together with a velocity of 25 metre per second mass of the other body is​

Answer 1

Explanation:

By using law of conservation of momentum..

$m1 \times v1 = m2 \times v2 \\ \\ 2 \times 40 = m2 \times 25 \\ \\ m2 = \frac{80}{25} \\ m2 = 3.2kg$