Answer to Question #191160 in Classical Mechanics for Mike

Question

In a ball game a 70 kg player is running at 10 m/s when he is hit by the other player he bounces off in the opposite direction at 2 m/s. What is the players change in momentum?

Answer 1

$\text{before collision:}$

$m = 70;\vec{V_1}=10;$

$\vec p_1=m*\vec{V_1} = 10*70 = 700$

$\text{after collision:}$

$m = 70;\vec{V_2}=-2;$

$\vec p_2=m*\vec{V_2} = -2*70 = -140$

$\Delta p= \vec p_2-\vec p_1= -140-700 =-840kg*\frac{m}{s}$

$\text{Answer: }\Delta p=-840kg*\frac{m}{s}$