Gravity And Air Resistance example essay topic

1,615 words
My topic for the science fair is " Which falling objects fall the fastest? ". Many factors affect the speed of aerodynamics such as the different forces on the object. The aerodynamics of the object and the physics surrounding the object.

Great scientists have studied falling objects such as Galileo Galilei and Sir Isaac Newton. I will discuss their lives, experiments and scientific findings. Aerodynamics is the study of force on an object. It has been called the science of flight. Aerodynamics consists of two Greek words. Aerio's means " concerning the air ", while dynam is means " powerful".

The wind duct is the basic experimental tool in the studies of dynamics. The three main forces used in aerodynamics are the lifting force, the drag force, and the weight force. Aerodynamics is technically the science that was used to develop flying machines, such as helicopters, airplanes, jets, and rockets. Aerodynamics principles are primarily concerning flight. However, aerodynamics principles are used in designing automobiles and train bodies. Since aerodynamics also studies gases in the air, aerodynamics help determine frictional events in gas ducts and it also helps chart the flows of the pollutants in the air.

It has been found that people have been interested in aerodynamics for thousands of years. Aerodynamics not only involves the motion of the object (s), but also the reaction of air to the object. When aerodynamics has plenty of rolling components, you then will see friction. Friction is a force that resists the relative motion or tendency to such motion of two bodies in contact. Physics is the study of matter and energy and their reactions. The word physics comes from four main languages.

Although strange, these four languages all pronounce physics the same way or they are very close. These four languages are Old French, Greek, Latin, and Middle English. Middle English is the English language from 1100 to 1500. Isaac Newton was the person who experimented with many areas of physics, but it was Galileo Galilei who discovered that all items fall at the same speed without air. Newton discovered that forces do not cause motion; they cause acceleration. Newton also discovered that a force is not needed to keep an object in motion.

Newton conducted several experiments. His most famous experiment happened in his backyard. He was sitting under an apple tree reading a book when an apple fell on his head. After he recovered from the bump, he began to wonder.

He thought about why the apple fell. Why couldn't the apple go up, or left, or right? Why did it go down? In his experiments, he found that an invisible force is pulling us down and keeping everything on the ground. This explained why the apple fell down and not in any other direction. Newton figured out that the force keeps everything on the earth.

He discovered that the force even held the atmosphere around the earth. Newton called this force gravity. For example, when you jump, you come back down to earth. If there was no gravity, you would float up and disappear into space.

He also discovered different planets have more or less gravity. For instance, Pluto has almost the same amount of gravity as earth, but the moon has much less gravity than the earth. If you jumped on the moon, it would take you more time to get down. Since there is less gravity on other planets, their atmosphere does not keep in much oxygen, thus it is harder to breathe on other planets. That is why astronauts wear spacesuits, to give them air. Because planets with weak atmospheres cannot hold in much heat, it is cold on the other planets, except for those close to the sun.

Since we have already figured out who discovered gravity in the physics section, then we will go straight to what gravity does and how it affects us. Gravity holds the atmosphere. The atmosphere holds heat and air as well and it blocks us from the sun's harmful rays. Without the atmosphere we would all die.

We would either choke from lack of air, be burned to death by the suns harmful and deadly rays, or we would freeze to death. Gravity holds everything on the earth together. Without gravity, we would die. On other planets you will realize that there is no signs of life.

As I mentioned earlier, this is due to the fact that the other planets have a weak pull of gravity. This results in the other planets having a weak atmosphere. Since there is a weak atmosphere, it does not hold in heat, air, and it does not keep the sun's harmful and deadly rays from reaching the surface of the planet. Take Mercury for example.

Since there is a less pull of gravity, when you jump up, it will take you more time to come down. Though the earth's gravity is very strong, everything is pulled down with the same force of gravity, no matter the shape or size. Just like the earth, the moon and the other planets have the same pull of gravity on all objects. But, since there is a different pull of gravity on each planet, you will weigh differently on each planet. This is because no two planets have the same pull of gravity. On each planet, you will experience the same pull of gravity until you leave the atmosphere.

Free-falling objects all fall at the same speed when in a vacuum no matter the shape or size (a vacuum is a closed container where there is no air). A free-fall is an object that is moving only because of the action of gravity. Technically, a free-fall only happens when there are objects falling in a vacuum. In a vacuum, a pound of feathers falls just as fast as a pound of bricks. An elephant would fall as fast as an ant.

A school bus would fall at the same speed as a piece of sand. We do not live in a vacuum-type environment. We live in a world filled with air and air slows things down. This is called air resistance. Because of air resistance, an ant would fall slower than an elephant. Free-falling objects have no force when they are falling, except for gravity of course, but only in a vacuum.

Otherwise, there would be gravity and air resistance. Under these circumstances, all free-falling objects fall at the same acceleration, no matter the mass. In a free-fall, an ant will not have the same gravity as a school bus. However, since there is no air to slow things down, the objects will hit the ground at the same time.

No two objects have the same force of gravity. When there is air resistance, the bus would fall first because it has more mass and it would be harder for the air to slow it down. The ant would hit the ground second because it has smaller mass and the air would slow it down much easier than it could slow down the bus. But, in a vacuum, the mass and shape of an object do not matter. This is because all objects fall at the same rate in a vacuum. Air resistance, also called wind resistance, is when air slows down a falling object.

As an object falls through the air it encounters some air resistance. Air resistance happens when air molecules collide with an object's leading surface. Air resistance depends on the speed of the falling object. When an object reaches a point where the air slows it down to where it stops accelerating, it is called a terminal velocity. Take a car and a feather for example. A feather will hit a terminal velocity and will slow down.

The car will not hit a terminal velocity. Thus, it will hit the ground first. But, there is only air resistance inside of atmospheres. In plain space, there is no air resistance.

If you jumped, you would float up, up, and away. People spend their lives trying to figure out more about air and air resistance. There was tons of stuff on Google, trust me! These people found out that the thickness of the air changes the amount of air resistance there is.

Drag force, which is the force that tries to drag you up, is weaker than gravity. The drag force plays a crucial role in all speed-related sports. The drag force is the most important factor in swimming. The drag force affects vertical motion too. The drag force affects skydivers with parachutes.

The wind fills the parachutes and slows the skydivers down. In conclusion, there are many types of forces that are used in free falling such as, air resistance, gravity, terminal velocity, the drag force, and other frictional forces. There is so much information on free falling and I have barely made a dent in it. If you would like to find out more information about air resistance, free falling, or any other forces, just check my bibliography.