Conservation of Linear Momentum of astronaut

AI Thread Summary
An astronaut in space ejects gas from a propulsion unit, resulting in a recoil velocity of -30 m/s while the gas is expelled at 32 m/s. The astronaut's mass after gas ejection is 160 kg, leading to the application of the conservation of momentum principle. The equation m1vf1 + m2vf2 = 0 is used, where m1 is the astronaut's mass and vf1 is his velocity, while m2 and vf2 represent the mass and velocity of the ejected gas. Solving the equation yields a mass of 150 kg for the ejected gas, confirming the calculations are correct. The discussion effectively illustrates the application of linear momentum conservation in a practical scenario.
rmarkatos
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I am pretty sure i have this question correct but i want to make sure it is likely to show up on a test

An astronaut is motionless in outer space. Upon command the propulsion unit strapped to his back ejects some gas with a velocity of 32m/s and the astronaut recoils with a velocity of -30m/s. After the gas is ejected the mass of the astronaut is 160kg. What is the mass of the ejected gas?

well after looking at external and internal forces they should both equal zero.
So i found that Pf=Pi is that correct? But the initial conditions are zero because the astronaut was motionless in outer space. I am going to call m1 and vf1 the astronaut and m2 and vf2 the propulsion unit.

m1vf1+m2vf2=0

160kg(-30m/s) + m2(32m/s)=0
-4800kg m/s +m2(32m/s)=0
m2(32m/s)=4800kg m/s

solving for m2 i got 150kg. is that correct?
 
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Yes, appears correct.
 

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