Question

An astronaut with a mass of `75 kg` is floating in space. If the astronaut throws an object with a mass of `7 kg` at a speed of `1/4 m/s`, how much will his speed change by?

Answer 1

`v_1=42.86ms^-1`

Explanation:

Conservation of momentum clearly implies here that
`m_1v_1=m_2v_2`

Those of subscript `1` denote the astronaut and those of `2` denote the object. So,
`75*v_1=7*1/4\impliesv_2=75*4/7`

Solve that and the answer above is what you get.