If the Sun suddenly turned off, we would not know it until its light stopped coming. How long would that be, given that the Sun is $1.50\times 10^{11}\text{ m}$ away?

Video Transcript

This is College Physics Answers with Shaun Dychko. This question asks us to find out how much time would it take for us to know when the sun has been turned off. Because it will take some time for the last ray of light that it emitted to reach us and we know the distance to the Sun and we can solve for t by dividing both sides by the speed of light and so the time will be the distance from the Sun to divided by speed of light So that's 1.5 times 10 to the 11 meters divided by 3 times 10 to the 8 meters per second, which is 500 seconds and divide that by 60 seconds to get 8.33 minutes