Find the magnitude of the free-fall acceleration at the orbit of the Moon (a distance of 60RE from the center of the Earth with the radius of RE). Use the gravitational acceleration on the surface of the Earth is 9.8m/s2.

The magnitude of the free-fall acceleration at the orbit of the Moon is (, where ).

Explanation:

According to the Newton's Law of Gravitation, free fall acceleration (), in meters per square second, is directly proportional to the mass of the Earth (), in kilograms, and inversely proportional to the distance from the center of the Earth (), in meters:

(1)

Where:

- Gravitational constant, in cubic meters per kilogram-square second.

- Mass of the Earth, in kilograms.

- Distance from the center of the Earth, in meters.

If we know that , and , then the free-fall acceleration at the orbit of the Moon is:

28. evolution

29. environment, survive, offspring  

explanation:

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me