Peter and fred are skateboarding in a large semicircular halfpipe. peter starts out from rest at a height h and collides with fred standing at the bottom. peter and fred have about the same mass. after the collision, which height will fred reach?

The answer is h/4

Explanation:

When Peter collides with Fred, the collision is inelastic & they both proceed with a velocity of V/2.

let m represent the masses for Peter & Fred

v represent the initial velocity of Peter

V represent final velocity of both of them

mv + 3m × 0 = (m+m)V

V = v/2

Using the expression; H = v² / 2g Eqn 1

Upon substitution of V/2 into Eqn 1 above,

H = (V/2)² / 2g

H = (V²/4) ÷ 2g

Therefore height will be h/4