What is the average time taken for light emitted from the surface of the Sun to travel one Astronomical Unit (1 AU) and reach planet Earth?
Answer and explanation
Correct answer: D. About 8 minutes and 20 seconds
- Step 1: One Astronomical Unit (1 AU) is the mean distance between the Earth and the Sun, approximately 149,597,870 kilometers.
- Step 2: Dividing this distance by the speed of light in vacuum (c ≈ 299,792 km/s) gives roughly 499 seconds, which corresponds to 8 minutes and 19 to 20 seconds.
Answer
About 8 minutes and 20 seconds
Why not the others: 'About 1 minute and 30 seconds' 1 minute 30 seconds is far too rapid given the distance of 149.6 million kilometers; 'About 20 minutes' 20 minutes is roughly the time light takes to reach Mars at its greater orbital distance; 'Light reaches Earth instantaneously' Light travels at a finite velocity of approximately 299,792 kilometers per second in vacuum.
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