Question

An astronaut with a mass of `105 kg` is floating in space. If the astronaut throws an object with a mass of `3 kg` at a speed of `7/8 m/s`, how much will his speed change by?

Answer 1

I found `0.025m/s` in the opposite direction (wit respect to object).

Explanation:

We can use conservation of momentum along, say, the`x` direction and suppose the astronaut initially at rest:

With our data:
`(105*0)+(3*0)=(105*v_A)+(3*7/8)`
`105v_A=-21/8`
`v_A=-0.025m/s`
With `-` sign to indicate the opposite direction with respect to the direction of the object.