(a) How much time does it take light to travel from the moon to the earth, a distance of 384,000 km?
(b) Light from the star Sirius takes 8.61 years to reach the earth. What is the distance from earth to Sirius in kilometers?
(a) How much time does it take light to travel from the moon to the earth, a distance of 384,000 km?
(b) Light from the star Sirius takes 8.61 years to reach the earth. What is the distance from earth to Sirius in kilometers?