Consider a pulse of laser light aimed at the Moon that
bounces back to Earth. The distance between Earth and
the Moon is 3.84 * 108 m. Show that the round-trip
time for the light is 2.56 s
During a solar eclipse, the moon (of mass 7.36 × 1022 kg), Earth (of mass 5.98 × 1024 kg), and Sun (of mass 1.99 × 1030 kg) lie on the same line, with the moon between Earth and the Sun.
1.What gravitational force is exerted on the moon by the Sun? The universal gravitational constant is 6.673 × 10-11 N · m2/kg2,the Earth-moon distance is 3.84 × 108 m, and the Earth-Sun distance is 1.496 × 1011 m.
Answer in units of N.
2.What gravitational force is exerted on the moon by Earth?Answer in units of N.
3.What gravitational force is exerted on Earth by the Sun? Answer in units of N.
To calculate the round-trip time for the light, we need to find the time it takes for the laser pulse to travel from Earth to the Moon and then back to Earth.
Given:
Distance between Earth and Moon = 3.84 * 10^8 m
The speed of light in a vacuum is approximately 3 * 10^8 meters per second (m/s).
To calculate the time it takes for the light to travel from Earth to the Moon, we can use the formula:
Time = Distance / Speed
Time = (3.84 * 10^8 m) / (3 * 10^8 m/s)
Simplifying, we get:
Time = 1.28 s
Since the round-trip time includes the time it takes for the light to travel back to Earth, we multiply the one-way time by 2:
Round-trip Time = 2 * 1.28 s
Round-trip Time = 2.56 s
Therefore, the round-trip time for the light to travel from Earth to the Moon and back is 2.56 seconds.