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Momentum attained by a laser beam

  • Thread starter jstrike
  • Start date
  • #1
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A small spaceship, with a mass of 1500 kg (including occupants), is at rest in outer space with negligible gravitational forces acting on it. If the astronaut turns on a 10kW laser beam that points out of the ship into the deep of space, what speed will the ship attain in 1 day because of the momentum carried away by the beam?

W=J/s
10000W=10000J/s
10000*60*60*24= 864000000J
864000000=.5*1500v^2
v= 1073.31

where do i go from here?
 

Answers and Replies

  • #2
mgb_phys
Science Advisor
Homework Helper
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What's the equation for the momentum of a photon and it's energy.
How many photons/second of this momentum can you generate from this laser power
 
  • #3
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E=pc
p= h/ lamda
E= hc/ frequency
play with these formulas by sub. then you should get it.. by the way the p=momentum
 

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