# Problem: a) An 80 kg quarterback jumps straight up in the air right before throwing a 0.43 kg football horizontally at 15 m/s. How fast will he be moving backward just after releasing the ball?b) Suppose that the quarterback takes 0.30 s to return to the ground after throwing the ball. How far will he move horizontally, assuming his speed is constant?

###### FREE Expert Solution

a) The expression for the conservation of momentum:

$\overline{){{\mathbf{m}}}_{{\mathbf{0}}}{{\mathbf{v}}}_{{\mathbf{0}}}{\mathbf{=}}{{\mathbf{m}}}_{{\mathbf{f}}}{{\mathbf{v}}}_{{\mathbf{f}}}}$

solving for v0:

###### Problem Details

a) An 80 kg quarterback jumps straight up in the air right before throwing a 0.43 kg football horizontally at 15 m/s. How fast will he be moving backward just after releasing the ball?

b) Suppose that the quarterback takes 0.30 s to return to the ground after throwing the ball. How far will he move horizontally, assuming his speed is constant?