Question

The new horizons spacecraft sent a microwave signal as it reaches pluto. The average distance of pluto from the sun is 5.91(10)^12 metres and the average distance of earth from the sun is 1.50(10)^11 metres. If the earth is directly between the sun and pluto, how long did it take the signal to travel from pluto to the earth? Give your answer in seconds, minutes, and hours.

Answer 1

Distance from earth to Pluto
5.91(10)^12-1.50(10)^11 =57.6(10)^11 meters

Speed of light = 3(10)^8 m/s

57.6(10)^11 / (3(10)^8) =
19200 seconds or
320 minutes or
5.33 hours