Name: Scott
Who is asking: Student

Question: A laser beam travelling at the speed of light bounces off the planet Neptune and returns to Earth in 29 960.72 s. The speed of light is 299 792.5 km/s. How far from Earth is Neptune?...... How do i find the answer to this. Thanks for your help...



Since the laser beam takes 29 960.72 s to travel to Neptune and back it takes half that time, 14 980.36 s, to travel from the Earth to Neptune. The laser beam travels 299 792.5 km every second and hence in the 14 980.36 seconds it takes to get to neptune it has travelled

299 792.5 14 980.36 km