Understand The Difference Between Gravity And Moons

One of the many questions people wonder is, why gravity differs on different planets and moons. In order to understand the answer of this question, one must know what gravity is. Gravity is the force of nature that attracts one body towards the center of the Earth, or any other physical body that has any kind of mass. Gravity is also in charge of the interactions that occur between particles and collections of matter, like the stars and the planets. Gravity depends on two different things, the masses of the two objects involved and the distance in between them. Gravity is stronger when matter that has a larger mass; therefore, when a person steps on the moon they feel weightless, this is because the moon has a lot less mass resulting in less gravity. (Brewter)
Before understanding how gravity acts, one must understand the difference between weight and mass. Weight and mass are two completely different things. The mass of a body is a measure of the amount of matter it contains. If you have an object, it takes a push to get it moving, but after that, it wants to stay in motion. Mass is the measure of how much inertia acts on a certain object with mass. Weight on the other hand is completely different. It is the amount of attraction between a person and any planet
or mass. Therefore, in order to have gravity, weight and mass must play their role. (Hipschman, 1997) The mass of an object does not change depending on its location, although weight does change when a person changes location. A few equations are used in physics to calculate the gravity in different locations and as it varies. The force of gravity depends on a person’s mass and the mass of the planet they are standing on. For example, if the planet you are standing on is twice as massive, gravity will pull you twice as hard. (Cessna, 2009) Another factor acting upon gravity would be the distance between a person and the center of a planet; the farther away you are the weaker the gravitational pull will be. The gravitational force becomes weaker rapidly; to calculate the gravitational pull as you move farther from the center you would use this equation: (1)
According to Newton’s Law of universal gravitation two bodies, exert a force that is proportional to the product of masses and inversely proportional to the square of the distance found between them, and the planet with the larger mass will have more gravity than a smaller planet. The second equation would look like this: (2)
Not only is a person a different weight on different planets, but also can weigh something else in another location on the Earth.
Gravity varies with latitude. A person weighs .5% more when they are closer to the North and South poles, compared to standing by the equator. The earth is not completely rounded and is actually more of a “squashed” sphere; therefore, this causes the radiuses of the equator and the poles to be slightly different. The gravitational acceleration is 9.78 m/s2 at the equator and 9.83 m/s2 at the north and south poles (Masters, 2002). These different gravitational accelerations is also known as centripetal acceleration, and it has a minute change on different locations on the
Earth.
Gravitational fields also have a huge effect on the variations of gravity. If Earths gravitational field were stronger than it currently is, people would be pushed strongly to the surface and crushed against it. Therefore, mass and weight is not the only factor as to why peoples weight changes from planet to planet; gravitational fields hold a big role as well. Mass has nothing to do with gravitational fields, Saturn has a lot more mass than Uranus, but their fields are the same (Gibs, 2010). The gravitational field on Earth is 9.8m/s2. Every person has a gravitational field they are just very weak, and cannot be felt.
It has always been a huge question as to why gravity was different on other planets, and why people feel “weightless” on the moon. The universe is very complex, but everything works the way it does for a reason. Without gravity, there would be no order and everything would be in a big hodgepodge; gravity holds everything in its place. Without the different forces of gravity, the universe would not orbit the way it does. The simple answer to the question of why gravity differs would be because the difference of mass, weight, latitude, and gravitational fields. Gravity is everywhere; there is no escaping it. Life would be fun for a while without it, just floating around, but after a while people would want to put their feet back safely on the ground. Gravity is always attracting even if people cannot feel it. Gravity is the weakest of the four forces of nature, but it is the force that presides over the movement of the entire universe.