Calculating Trip Time for Laser Beam to Moon and Back

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SUMMARY

The calculation of the time it takes for a laser beam to travel to the Moon and back, given a distance of 3.8 x 108 meters, results in approximately 2.6 seconds. The initial attempt incorrectly applied gravitational acceleration in the formula, which is unnecessary for light travel as photons are massless and unaffected by gravity in this context. The correct approach involves using the speed of light, approximately 3 x 108 m/s, to determine the time directly without considering acceleration.

PREREQUISITES
  • Understanding of the speed of light (3 x 108 m/s)
  • Basic knowledge of kinematics equations
  • Familiarity with the concept of massless particles
  • Ability to perform unit conversions and basic arithmetic
NEXT STEPS
  • Research the properties of photons and their behavior in gravitational fields
  • Learn about the speed of light and its implications in physics
  • Explore kinematics without acceleration for constant speed scenarios
  • Study the differences between classical mechanics and relativistic effects
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Students in physics, educators teaching kinematics, and anyone interested in the principles of light travel and basic astrophysics.

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Homework Statement


How long would it take a laser beam to go to the Moon and back if the distance to the Moon is 3.8 x 10^8m?


Homework Equations


a=2d/t^2
d=v1 t + 1/2a t^2

The Attempt at a Solution


a=2d/t^2
9.8m/s(Gravity)=2(7.6x10^8)/t^2
t^2=15.2x10^8/9.8
t= 12453.99698 secs

P.S the answer at the back of the book says 2.6sec
 
Physics news on Phys.org
Why are you including acceleration? Do you know what the speed of light is?
 
photons, being massless, are not affected by gravity... at least not appreciably for your problem
 

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