Ultraviolet light from a distant star is traveling at 3.0 × 108 m/s. how long will it take for the light to reach earth if it must travel 4.0 × 1016 km?

We can apply the formula showing the relationship between speed, time, and distance to compute the time taken for the light to reach the earth. we have



first, we need to make sure that the units are uniform. thus, the distance is will be equal to (4.0 x 10¹⁶)(1000) = 4.0 x 10¹⁹ m.

now that all units are uniform, we have




thus, the uv light will take 1.3 x 10¹¹ seconds to reach the earth.

answer: 1.3 x 10¹¹ seconds