Momentum. resulting velocity. Rocket

AI Thread Summary
The discussion centers on calculating the resulting velocity of an astronaut using a rocket backpack in space. The astronaut and equipment weigh 1,960.0 N on Earth, and the rocket backpack exerts a force of 100 N for 2.0 seconds. The user calculates the change in momentum as 200 kg·m/s, then applies the momentum formula to find the resulting velocity. The final calculation yields a velocity of 1 m/s, confirming the approach is correct. The discussion concludes with validation of the calculations presented.
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[SOLVED] Momentum. resulting velocity. Rocket

Homework Statement



On earth, an astronaut and equipment weigh 1,960.0 N. While weightless in space, the astronaut fires a 100 N rocket backpack for 2.0 s. What is the resulting velocity of the astronaut and equipment?

I have to be missing something. I tried using every formula given to me in class and I cannot get anywhere. Please help. Thanks.

Homework Equations



p=mv
Ft= (mf)(vf)-(mi)(vi)
Ft=ma+v(difference of m/t)
m1v1=m2v2

The Attempt at a Solution


I tried a few and can't get a relevant answer. I really do not know where to begin with the rocket.
 
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Don't worry about the rocket itself. You only care about what it does. It applies a constant force over a specified time? How does this affect the astronaut in terms of momentum?
 
difference of momentum= (100N)(2.0s) = 200kgm/s

200kgm/s= (1960N/ 9.8m/s^2) V

V=1m/s

I first found the difference of momentum which is force * time. then used the equation momentum=mass*velocity. Is this correct?
 
rtamplain said:
difference of momentum= (100N)(2.0s) = 200kgm/s

200kgm/s= (1960N/ 9.8m/s^2) V

V=1m/s

I first found the difference of momentum which is force * time. then used the equation momentum=mass*velocity. Is this correct?

Looks Good!:smile:
 
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