Question

2. O/N 15/P12/Q14
Two identical spheres X and Y approach each other with the speeds shown and undergo a headon elastic
collision
4ms-
2 ms-
x
Y
What are the velocities of the spheres after the collision?​

Answer 1

Answer:

Explanation:

Let the positive direction be toward the right,

In perfect elastic collision, the momentum and kinetic energy are conserved.

Relative speed of approach =  relative speed of separation.......(I)

Approach means getting closer to each other

Separation means getting away from each other  

Relative speed of approach = 5+15=20 m/s

Suppose that the velocity of X is positive, the value of v would be negative and negative indicate the direction of X is in  after the collision.

Relative speed of separation = 7-v

From equation (I)

20=7−v

−v=13 m/s

So, The speed of ball X is 13 m/s to the left after collision.