Question

The freight cars a and b have a mass of 20mg and 15mg respectively.after collision

Answer 1

This question is testing on the concept of momentum.

Initial momentum = Final momentum

Momentum = mass × Velocity

For the two bodies let Ua be the velocity of a and Ub be the velocity of b.

We want to find the final velocity by which the two move

This is V.

Substituting in the formula :

(20/1000000) × Ua + (15/1000000) × Ub = (20/1000000 + 15/1000000) V

V = {(20/1000000)Ua) + (15/1000000)Ub} / {(20/1000000)+ (15/1000000)}