Final answer:
If the Sun turned off, we would become aware after 500 seconds, the time it takes for sunlight to travel the 150,000,000 km from the Sun to Earth at the speed of light, 299,792 km/s. This delay is because light travels at a finite speed, and events observed are actually from the past due to light's travel time. The correct option is a.500 sec
Step-by-step explanation:
If the Sun suddenly turned off, we would only become aware of this event once the last of its light reached us. Since light takes time to travel across space, and the Sun is 150,000,000 kilometers away from Earth, we can calculate the time it takes for sunlight to reach us.
First, we need to use the speed of light in a vacuum, which is approximately 299,792 kilometers per second. By dividing the distance from the Sun to Earth by the speed of light, we find that light from the Sun takes approximately 500 seconds to reach Earth. Hence, if the Sun 'turned off,' it would take us 500 seconds to notice that change.
This is equivalent to saying that any event we observe on the Sun, such as a sunspot, actually occurred about 8 minutes and 20 seconds earlier.
Astronomically, we measure distances in terms of the time light takes to travel them. This is why astronomers often refer to distances in terms of light minutes, light hours, or light years, such as the 4.24 light years to Alpha Centauri, our nearest star system after the Sun.
The correct option is a.500 sec