The distance from the sun to Earth is 1.496 * 108 km. How long does it take light to travel from the sun to Earth?

Video transcript

Hey everyone In this example, we need to calculate the amount of time it takes for light from the moon to reach the Earth. Were given the distance between the moon and earth as 384,400 km. So what we're starting from is from units of kilometers we're going to convert to meters and that because we want our final unit to be time, we're going to go from meters into seconds. So starting out with our kilometers were given 384, km as our distance from the moon to the Earth. And we're going to go from kilometers in the denominator into meters. In our numerator, we should recall that our prefix kilo tells us stuff for one kilometer. We have 10 to the third power meters. Now we're able to cancel out kilometers and now we're going to go from meters in our denominator, two seconds in our numerator. So we should recall the conversion factor that we have one second equal to three times 10th of the eighth power meters. So we can plug that in. So we have three times 10 to the eighth power meters in our denominator and one second in our new meter and now we can go ahead and cancel out meters leaving us with time in seconds as our final unit. This is going to give us a value equal to 1.28 seconds as our amount of time it takes for the light from the moon to hit the earth and this would be our final answer to complete this example. So I hope that everything we read was clear. Our answer 1.28 seconds will correspond with choice a and if you have any questions, just leave them down below and I'll see everyone in the next practice video.