Question

When two spheres of equal masses undergo glancing elastic collision with one of them at rest, after the collision they will move

• A. opposite to one another
• B. in the same direction
• C. together
• D. at right angle to each other

Answer 1

The correct option is D

at right angle to each other

Step 1: Given information

One sphere is moving and the other is at rest, and they have the same mass.

Step 2: For sphere 1 (in motion)

Say initial velocity is $u_1$, and momentum is $p$.

And final velocity after the collision is $v_2$

Step 2: For sphere 2 ( at rest)

Initial velocity is $0$, and initial momentum is $0$.

And final velocity after the collision is $v_2$

As its a type of elastic collision, both the momentum and energy are conserved in this process.

Now applying the conservation of linear momentum and conservation of energy we can see that, ${\theta }_1+{\theta }_2={90}^o$.

So, for a glancing elastic collision of two bodies having the same mass, one moving and one at rest will move perpendicular to each other after the collision.