Question

Two astronauts are floating together with zero speed in a gravity-free region of space. The mass of astronaut A is 110 kg and that of astronaut B is 74 kg. Astronaut A pushes B away, with B attaining a final speed of 0.4. The final recoil speed of astronaut A is:

Answer 1

Answer:

The recoil speed of Astronaut A is 0.26 m/s.            

Explanation:

Given that,

Mass of astronaut A, $m_A=110\ kg$

Mass of astronaut B, $m_B=74\ kg$

Astronaut A pushes B away, with B attaining a final speed of 0.4, $v_B=0.4\ m/s$

We need to find the recoil speed of astronaut A. The momentum remains conserved here. Using the law of conservation of linear momentum as :

$m_Av_A=m_Bv_B\\\\v_A=\dfrac{m_Bv_B}{m_A}\\\\v_A=\dfrac{74\times 0.4}{110}\\\\v_A=0.26\ m/s$

So, the recoil speed of Astronaut A is 0.26 m/s.