Question

An astronaut with a mass of `95 kg` is floating in space. If the astronaut throws an object with a mass of `7 kg` at a speed of `7/4 m/s`, how much will his speed change by?

Answer 1

`v_1=7.755ms^-1`

Explanation:

This concept is an issue of conservation of momentum.
That is, `m_1\vec{u_i}=m_1\vec{v_1}+m_2\vec{v_2}`

We know that initially the man was at rest. So, `u_i=0ms^-1`
So that makes our equation, `-m_1\vec{v_1}=m_2\vec{v_2}`
Disregarding the vectors/directions, it becomes `m_1*v_1=m_2*v_2`

We have `m_1=95kg`, `m_2=7kg` and `v_2=7/4ms^-1`
Substituting all these into the equation, we get
`95*v_1=7*7/4`

Now you see why `v_1` is soo dissuading to watch.