Question

1. If some unimaginable calamity destroyed the Sun, using the astronomical unit for the Earth-Sun distance and the value for the speed of light above, how long would we still have light after the Sun ceased to exist? (5)

Answer 1

8 minutes and 20 seconds

Step-by-step explanation:

Average Distance between Earth and Sun: 150 million km =
`1.5 * 10^(8)` km

Velocity of light:
`3 * 10^(8) \ m/s = 3 * 10^(5) \ km/s`

Time = Distance/Speed

or Time =
`1.5 * 10^(8) \ km` /
`3 * 10^(5) \ km/s`

= 5 * 100

= 500 seconds

⇒ Time = 8 minutes and 20 seconds