Problem 28 - University Physics with Modern Physics

Question

How long does it take light to travel from the Moon to the Earth? From the Sun to the Earth? From Jupiter to the Earth?

Step-by-Step Solution

Answer

Answer: It takes approximately 1.28 seconds for light to travel from the Moon to Earth, about 8 minutes and 19 seconds from the Sun to Earth, and around 34 minutes and 55 seconds from Jupiter to Earth when they are closest.

Step 1: Calculate time for light to travel from the Moon to Earth

Using the distance between Earth and the Moon (384,400 km) and the speed of light (300,000 km/s), use the formula time = distance/speed: time = 384400/300000 time ≈ 1.28 seconds It takes roughly 1.28 seconds for light to travel from the Moon to the Earth.

Step 2: Calculate time for light to travel from the Sun to Earth

Using the distance between Earth and the Sun (149,600,000 km) and the speed of light (300,000 km/s), use the formula time = distance/speed: time = 149600000/300000 time ≈ 498.67 seconds It takes roughly 498.67 seconds, or about 8 minutes and 19 seconds, for light to travel from the Sun to the Earth.

Step 3: Calculate time for light to travel from Jupiter to Earth

Using the distance between Earth and Jupiter when they are closest (628,700,000 km) and the speed of light (300,000 km/s), use the formula time = distance/speed: time = 628700000/300000 time ≈ 2095.67 seconds It takes roughly 2095.67 seconds, or about 34 minutes and 55 seconds, for light to travel from Jupiter to the Earth when they are closest. Note that the time will be longer when Earth and Jupiter are farther apart.