1. an astronaut with a mass of 77.5kg is stuck in space floating 15.0m away from his ship.
his motion relative to the ship is 0 m/s. fortunately, he is holding a 2.0kg wrench. he throws
the wrench in the opposite direction of the ship at 12m/s. what is the wrench's change in
momentum?

24 kg m/s

Explanation:

The change in momentum of the wrench is given by:

where

is its final momentum

is its initial momentum

At the beginning, the wrench is at rest together with the astronaut, so its momentum is zero:

After it is launched, its momentum becomes

where

m = 2.0 kg is its mass

v = 12 m/s is its velocity (taking the direction of the wrench motion as positive)

Substituting,

So, the wrench's change in momentum is