Average Velocity Video Lessons

Concept

# Problem: Part AHow much time does it take light to travel from the moon to the earth, a distance of 384,000 km?Part BLight from the star Sirius takes 8.61 years to reach the earth. What is the distance to Sirius in kilometers?

###### FREE Expert Solution

Part A

Time, t:

$\overline{){\mathbf{t}}{\mathbf{=}}\frac{\mathbf{d}}{\mathbf{v}}}$

The speed of light c = 3.0 × 108 m/s

81% (306 ratings)
###### Problem Details

Part A

How much time does it take light to travel from the moon to the earth, a distance of 384,000 km?

Part B

Light from the star Sirius takes 8.61 years to reach the earth. What is the distance to Sirius in kilometers?