# The Law of Falling Bodies 1604

FallingObjects, according to the laws of motion formulated by newton in his Principia, accelerate until they reach a point when their rate of acceleration is zero and they move in a straight line until hitting something. The reality is rather more complex than that. The acceleration of an object falling under the influence of gravitational forces is not constant but changes over time. The change is not only dependent on the mass of the object but also on variations in air density and humidity as well as their size; smaller objects fall faster, heavier ones slower, and larger contents of air accelerate their rate of acceleration. There are also variations depending on which way the body is oriented such factors as friction with the ground or wind resistance in the direction of fall can increase or decrease acceleration. This article discusses these factors and how they affect falling objects.

## What is Gravity?

Gravity is the force of attraction or the pull between all bodies in the universe. This force is what compels objects to fall to the ground. It is also responsible for keeping the earth and the other planets in orbit around the sun. Gravitational force can be thought of as the glue that holds the universe together. It is the force that holds all matter together, including the earth and the moon. It also keeps the earth rotating around the sun. Gravitational force is most powerful when the two objects being attracted are very large. On the earth, gravity keeps all objects, including humans, glued to the surface. If you jump, you'll quickly come to the ground again. You can't float in the air like a bird.

## Falling Body Velocity

The speed of a falling body is dependent on the properties of the object, but also the air density. The force of air friction provides a slowing effect, known as drag. Most falling bodies accelerate until they reach a terminal velocity that is dependent on the size of the object and its orientation in the air. The terminal velocity of a falling body is the speed that the drag force just equals the force of gravity on the object and the object accelerates at a rate equal to the rate at which it started falling. The terminal velocity is reached when the air resistance of a body is equal to the gravitational force of the body.

## Terminal Velocity

As mentioned, the terminal velocity of a falling body is the speed that the drag force just equals the force of gravity on the object and the object accelerates at a rate equal to the rate at which it started falling. The terminal velocity is reached when the air resistance of a body is equal to the gravitational force of the body. The terminal velocity of a falling body is dependent on the properties of the object, but also the air density. Smaller objects fall faster, heavier ones slower, and larger contents of air accelerate their rate of acceleration. There are also variations depending on which way the body is oriented such factors as friction with the ground or wind resistance in the direction of fall can increase or decrease acceleration.

## Drag and Air Density

The drag of a falling object is proportional to the cross-sectional area of the object as well as the air density. The force of drag is dependent on the kinetic energy of the object, which is proportional to the mass of the object times the velocity of the object. As the density of the air decreases, the kinetic energy of the object decreases, and the drag force increases. This is why falling bodies that drop through a void or vacuum accelerate much more rapidly than if they fall through the air. Gravity is reduced in a vacuum but air resistance remains the same, so the rate of acceleration is higher. The coefficient of drag is a measure of the ability of an object to resist airflow. A streamlined shape generally has a lower drag coefficient than a rough shape.

## Humidities and the Coefficient of Drag

The coefficient of drag is affected by the humidity of the air surrounding the falling object. The more humid the surrounding air, the higher the coefficient of drag. This is because water molecules are heavier than air molecules. As a result, the air is dense and it takes more momentum to keep an object moving at a given velocity. One interesting fact is that the coefficient of drag of a falling object is greater when the humidity of the air is lower. This is because the air is less dense, and the object experiences less resistance to airflow. The coefficient of drag is also greatly affected by the shape of the falling object. A streamlined shape has a lower coefficient of drag than a rough shape.

## Rotational Effects on Falling Bodies

Falling bodies that rotate end up rotating faster and accelerating more toward the end of their fall. The reason for this is that the air has a higher coefficient of drag on the rear of the falling body than on the front, so the air on the rear has to generate more momentum than it would in an object that is not rotating. This means that the rear of the object experiences a higher drag force than the front, and this rotational effect can be calculated. It is important to note that this effect is only observed in objects that are cylindrical or have a flat surface.

## The Importance of Altitude in Falling Object Acceleration

As explained above, the acceleration of a falling body is not constant but varies over time. The change is not only dependent on the mass of the object but also on variations in air density and humidity. The altitude of the falling body is also a factor as the density of the air changes with altitude. Cooper (2006) states that we can see the effects of variation in air density and altitude by observing a feather drop and a coin drop. He states that the feather will fall at a much faster rate than the coin because it takes more air resistance to slow down the coin because of its shape and size. Cooper also states that the feather will gradually slow down at a much greater rate because the air gets less dense with altitude and the feather experiences much more drag than the coin. While the coin will continue to accelerate until it reaches its terminal velocity, the feather will experience a reduction in the effect of gravity due to the reduction in air density and will gradually descend at a much slower rate than the coin.

## Conclusion

Falling objects are extremely interesting, and they can teach us a lot about the physics behind them. The law of falling bodies is an interesting topic, and it can be studied from numerous perspectives.