The average mass for a spacesuit plus astronaut is 191 kg. The average speed for air molecules inside the space suit is 549 m/s and has a density of 1.05 kg/m^3. If the air escapes Whatney's suit at 0.020 m^3/s moving directly away from him, how fast will he be going after 8.1 seconds (in m/s) if he started from rest?

The value  is    

Explanation:

From the question we are told that

    The mass of the spacesuit plus astronaut is  

     The average speed of air molecules is  

     The density of air molecule is  

      The acceleration of the air from Whatney's suit  is  

      The time considered is

Generally the mass of air that have left Whatney's suit after the time considered is mathematically represented as

=>    

=>      

Generally the momentum of the escaped air is  

=>        

=>        

Generally from the law of momentum conservation

Here is the momentum of the astronaut at the considered time  

Here  is the velocity of the astronaut at the considered time  

=>      

=>        

you have to draw the persons position over there