# Newton's First law and KT of Gases

• VelvonVeden
In summary, my instructor mentioned that we might be required to Know, state, and apply this theory to one of newtoms laws, without specifying which one. After thinking it over, I decided that it applied to Newton's First Law OR Newtons third law: An object in a state of rest or uniform motion will remain in that state unless an external force is exerted on it. For every action there is an equal and opposite reaction, and the application and explanation I have is this: since all the particles in a gas are identical and have the same mass, volume, and weight, when they collide with each other, they each exert a force on the other that is equal in magnitude and opposite in direction (3rd law).
VelvonVeden
One of the assumptions of Kinetic Theory states that:

A gas is a substance composed of many particles flying about randomly, colliding with one another and with the walls of the container.

My instructor mention that we might be required to Know, state, and apply this theory to one of newtoms laws, without stating which one.

After thinking it over, I decided that it applied to Newton's First Law OR Newtons third law:

An object in at a state of rest or uniform motion will remain at rest or in a state of uniform motion unless an force is exerted upon it.

For every actiont here is an equal and opposite reaction

The application and explation i have is this:

Since we assume that all the particles in a gas are identical and as such have identical masses, volumes and weights, when they collide with one another, they each exerts a force on the other that is equal in magnitude and opposite in direction ( 3rd law). This force sends the partcles away from each other, each following a straight path, moving at a constant velocity until it collides with another particle or the walls of the container (1st law ) and changes direction. The random nature of a particles motion comes from the continuous colliding and changing direction.

I also wanted to add this but it seems unrelated:

In a gas, each particle posses a net amount of kinetic energy. (KE) Since the collisions between particles are perfectly elastic, the net amount of KE in the gas remains constant.

However, the above explanation involves two laws, and I strongly believe he is looking for us to relate it to one. So

1) Is the above explanation accurate and acceptable?

2) Which law applies most the that assumption of the KT? And how so?

I don't really know what your instructor wants. Technically all of Newton's laws apply to a gas. I'd ask your instructor for clarification.

Something to think about: How do collisions in the gas affect the velocity of the fluid?

## 1. What is Newton's First Law?

Newton's First Law, also known as the Law of Inertia, states that an object at rest will remain at rest and an object in motion will remain in motion at a constant velocity, unless acted upon by an external force.

## 2. How does Newton's First Law apply to gases?

Newton's First Law applies to gases in the sense that a gas will continue to expand and fill its container unless acted upon by an external force, such as a change in temperature or pressure.

## 3. What is the Kinetic Theory of Gases?

The Kinetic Theory of Gases is a model that explains the behavior of gases in terms of the motion and interactions of their particles. It states that gas particles are in constant motion and collide with each other and the walls of their container, creating pressure.

## 4. How does the Kinetic Theory of Gases relate to Newton's First Law?

The Kinetic Theory of Gases is based on the principles of Newton's First Law. The constant motion of gas particles and their collisions with each other and their container walls are examples of an object in motion remaining in motion unless acted upon by an external force.

## 5. What are some practical applications of Newton's First Law and the Kinetic Theory of Gases?

Some practical applications of these theories include understanding and predicting the behavior of gases in various systems, such as in engines, refrigerators, and weather patterns. They also help to explain the relationship between temperature, pressure, and volume in gases, as seen in the ideal gas law.

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