Answer to Question #277630 in Physics for Kristine

Question

You are standing on a sheet of ice that covers the football stadium parking lot in Buffalo; there is negligible friction between your feet and the ice. A friend throws you a 0.400-𝑘𝑔 ball that is traveling horizontally at 10.0 𝑚/𝑠. Your mass is 70.0 𝑘𝑔. a) If you catch the ball, with what speed do you and move afterward? b) If the ball hits you and bounces off your chest, so afterward it is moving horizontally at 8.0 𝑚/𝑠 in the opposite direction, what is your speed after the collision?

Answer 1

a) The speed is

$$u=mv/M=0.06\text{ m/s}.$$

b) The speed can be found by momentum conservation:

$$0+0.4·10=0.4·(-8)+70·u,\\ u=0.103\text{ m/s}.$$