Question

The light from the Sun reaches Earth in nearly:

• A. 8 minutes
• B. 4 minutes
• C. 2 minutes
• D. 16 minutes

Hint:

Use time equals distance divided by speed, with the Sun-Earth distance about 150 million km and light speed 3 times 10 to the power 8 m/s.

Answer 1

The Correct Option is A

Step 1: Note the required data.
The average distance between the Sun and the Earth is about \(1.5 \times 10^{11}\) m, called one astronomical unit.
Step 2: Use the speed of light.
Light travels at about \(3 \times 10^{8}\) m/s in vacuum.
Step 3: Calculate the time.
Time = distance divided by speed = \(\dfrac{1.5 \times 10^{11}}{3 \times 10^{8}}\), which comes out to about 500 seconds.
Step 4: Convert to minutes.
500 seconds is close to 8 minutes and 20 seconds, which rounds to nearly 8 minutes.
Step 5: Rule out other options.
4 minutes and 2 minutes are too short for the real Sun-Earth distance. 16 minutes is roughly double the correct value.
Final Answer: A) 8 minutes.