Push-Away Problems Video Lessons

Concept

# Problem: An 80-kg quarterback jumps straight up in the air right before throwing a 0.43-kg football horizontally at 15 m/s . 1. How fast will he be moving backward just after releasing the ball?2. Which interaction will you analyze in this problem?A. The quarterback jumping off the ground.B. The quarterback throwing the ball.C. The ball encountering air resistance after being thrown.D. The quarterback landing back on the ground.

###### FREE Expert Solution

The conservation of momentum of the quarterback and the football is:

$\overline{){{\mathbf{m}}}_{{\mathbf{q}}}{{\mathbf{v}}}_{{\mathbf{q}}}{\mathbf{=}}{{\mathbf{m}}}_{\mathbf{f}\mathbf{t}\mathbf{b}}{{\mathbf{v}}}_{{\mathbf{f}}{\mathbf{t}}{\mathbf{b}}}}$

###### Problem Details

An 80-kg quarterback jumps straight up in the air right before throwing a 0.43-kg football horizontally at 15 m/s .

1. How fast will he be moving backward just after releasing the ball?

2. Which interaction will you analyze in this problem?

A. The quarterback jumping off the ground.
B. The quarterback throwing the ball.
C. The ball encountering air resistance after being thrown.
D. The quarterback landing back on the ground.