Two basketballs of equal mass are rolling toward each other at constant velocities. The first basketball (B1) has a velocity of 4.3 m/s, and the second basketball (B2) has a velocity of -4.3 m/s.

If these basketballs have a perfectly elastic collision, B1 will have a final velocity of , and B2 will have a final velocity

Explanation:

Velocity of B₁ = 4.3m/s

Velocity of B₂ = -4.3m/s

For perfectly elastic collision:, momentum is conserved

where,

m₁ = mass of Ball 1

m₂ = mass of Ball 2

v₁ = initial velocity of Ball 1

v₂ = initial velocity of ball 2

v'₁ = final velocity of ball 1

v'₂ = final velocity of ball 2

The final velocity of the balls after head on elastic collision would be

Substituting the velocities in the equation

If the masses of the ball is known then substitute the value in the above equation to get the final velocity of the ball.