Is motion of moon round the earth is simple harmonic motion?
OK, the Moon revolves around the Earth. Right? Right. The Moon revolves around the Earth but that is a bit of an over simplification. Our Moon is a very large object. Indeed, the Earth-Moon “system” could be properly thought of as a “double planet system”. No other pair in the Solar System are so close in size (except for Pluto’s main satellite, Charon, but they are an unusual pair for a lot of other reasons that I will not discuss at this time). The Earth’s diameter almost four times the diameter of the Moon. [The Earth’s diameter is 12,700 kilometers and the Moon has a diameter of 3,400 kilometers. That’s a difference of about four fold.] The Earth is bigger so it is the “primary” body and the Moon is its satellite, but the Moon is a very big satellite! However, size can be deceiving because it is gravity that affects orbits. All matter has mass and all mass attracts other masses by a force called gravity. The force of gravity depends upon the mass of the two objects and the distance
