A 150 kilogram astronaut in his space suit throws away a 3 kilogram wrench at a velocity of 8 m/sec. What is his resulting velocity?

Conservation of momentum:
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
150(0) + 3(0) = 150v₁ + 3(8)
v₁ = -0.16 m/sec

Magnitude of the resulting velocity = 0.16 m/sec
Direction of the resulting velocity: opposites that of the wrench

3*8=24kg*m/s
24/150=.16m/s