Momentum attained by a laser beam

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SUMMARY

The discussion focuses on calculating the speed attained by a spaceship due to the momentum generated by a 10 kW laser beam. The spaceship, with a mass of 1500 kg, achieves a speed of 1073.31 m/s after one day of continuous laser operation. Key equations used include the work-energy principle and the relationship between energy and momentum for photons, specifically E=pc and p=h/λ. The calculations demonstrate how to derive the momentum of the emitted photons and their impact on the spaceship's velocity.

PREREQUISITES
  • Understanding of classical mechanics, specifically the work-energy principle.
  • Familiarity with the concepts of photon momentum and energy.
  • Knowledge of the equations E=pc and p=h/λ.
  • Basic grasp of laser power and its conversion to energy over time.
NEXT STEPS
  • Explore the derivation of photon momentum using the equation p=h/λ.
  • Investigate the implications of laser propulsion in spacecraft design.
  • Learn about the efficiency of different laser types for propulsion applications.
  • Study the effects of varying mass on the acceleration of objects in space.
USEFUL FOR

Aerospace engineers, physicists, and anyone interested in advanced propulsion systems and the physics of laser technology.

jstrike
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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?
 
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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
 
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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