At a given point in its orbit, the moon is 2.4 x 10^5 miles from earth. How long does it take light from a source on earth to reach a reflector on the moon and then return to earth? (speed of light is 3.0 x 10^8 m/s) in dimensional analysis please help me
Time ==Distance / speed
[2.4 x 10^5] x 2 ==4.8 x 10^5 miles - distance from Earth to Moon AND back
1 mile ==1,609344 km
4.8 x 10^4 miles x 1.609344 km==772,485.12 km - distance from Earth to moon AND back.
1 km ==1,000 meters
772,485.12 km x 1,000 m ==772,485,120 meters - distance from Earth to moon ANd back.
772,485,120 / [3 x 10^8] ==2.5749504 seconds - time it takes light to go from Earth to Moon AND back.