Sample Momentum Problem

(Taken from page 76 of your text)

Problem

A 100-kg astronaut ejects a 500 g camera at a speed of 6.0 m/s.  The recoil speed of the astronaut will be what?

Solution

The camera weight :  500g x 1 kg/1000g = 0.5 kg

Momentum is conserved.

Initially the momentum of the astronaut with the camera is 0.0.

At the end, the momentum of the astronaut plus the camera still equals zero. 

The mass and the velocity of the astronaut are m_a and v_a .

The mass and the velocity of the camera are m_c and v_c .  Note that I have to use the camera weight in kg so units cancel out.

ta da!