Question

An astronaut with a mass of `95 kg` is floating in space. If the astronaut throws an object with a mass of `8 kg` at a speed of `3/8 m/s`, how much will his speed change by?

Answer 1

I found `0.03m/s` in the opposite direction of the object.

Explanation:

We can use conservation of momentum `vecp=mvecv`:
where:
`vecp_"before"=vecp_"after"`

assuming one direction only (along `x` for example) we get:
`cancel(95*0)+cancel(8*0)=95*v_f+cancel(8)*3/cancel(8)`
rearranging:
`v_f=-3/95=-0.03m/s` in the opposite direction of the object.