Question

An astronaut whose mass is 80 kg carries an empty oxygen tank with a mass of 10 kg. The astronaut throws the tank away with a speed of 2.0 m/s. With what velocity does the astronaut start to move off into space?

Answer 1

Answer:

The speed of the astronaut is 0.25 m/s in the opposite direction to the oxygen tank.

Explanation:

Using the conservation of linear momentum, we have:

$p_{initial}=p_{final}$

The initial momentum is zero because both of them are at rest, so we just have a final momentum.

$0=m_{astro}V_{f-astro}+m_{tank}V_{f-tank}$

$m_{astro}V_{f-astro}=-m_{tank}V_{f-tank}$

$V_{f-astro}=-\frac{V_{f-tank}m_{tank}}{m_{astro}}$

$V_{f-astro}=-\frac{2*10}{80}$

$V_{f-astro}=-0.25\: m/s$

Therefore, the speed of the astronaut is 0.25 m/s in the opposite direction to the oxygen tank.

I hope it helps you!