# What is the difference between the resistance force and the friction coefficient?

• I
• tymi9
In summary: But on the other hand frictional resistance is always at least as big as the other resistance forces combined.In summary, resistance force is the combined effect of all the other resistance forces, while frictional resistance is always at least as big as any other resistance force combined.
tymi9
Hi
I have been wondering what is the difference between resistance force and friction coefficient. While doing research online I could not find a clear answer. Maybe someone here will now

Well, the units for one. The friction force has units of Newtons, and the friction. Coefficient is dimensionless.

I will assume that "resistance force" is another name for the more common "frictional force".
When two surfaces are ~smooth it is approximately true that the friction force is proportional to how strongly the surfaces are pushed together (this is the Normal force). And so we write that $$F_{friction}=\mu N$$

tymi9 said:
Hi
I have been wondering what is the difference between resistance force and friction coefficient. While doing research online I could not find a clear answer. Maybe someone here will now
One is a force, the other is a ratio between two forces: normal and friction.

Oh ok now I get it. thanks

However, is there a way to calculate the friction coefficient?

Not in a simple way. You should well know that it depends upon a lot of different things (like cleanliness of surfaces, moisture, temperature, etc). I think you can look up measured values for various combinations of surfaces. And the supposition that the ratio is constant is does not always hold. It is overemphasized in introductory physics because the problems are easy to formulate !

jbriggs444, PeroK and bob012345
tymi9 said:
Oh ok now I get it. thanks

However, is there a way to calculate the friction coefficient?
It is not simple to calculate, but it is rather straightforward to measure.

hutchphd and bob012345
Let's just put here that resistance of an object can consist of multiple effects, friction is just one:
- Frictional resistance
- Form or pressure resistance (for not so aerodynamically shaped objects also called bluff body resistance)
- Wave resistance (only applicable to floating objects like ships)

So if you say what is the difference between a resistance force and frictional resistance force (I'm assuming both as a force now), then the resistance force usually contains frictional resistance but may contain other types of resistance as well, and is therefore always at least as big as the frictional resistance.

## 1. What is the resistance force?

The resistance force is a force that acts in the opposite direction of an object's motion, hindering its movement. It is caused by factors such as air resistance, friction, and gravity.

## 2. What is the friction coefficient?

The friction coefficient is a measure of the amount of friction between two surfaces in contact with each other. It is a dimensionless quantity that depends on the nature of the surfaces and the force pressing them together.

## 3. How are resistance force and friction coefficient related?

The resistance force and friction coefficient are related in that the friction coefficient is a factor that determines the amount of resistance force present between two surfaces. The higher the friction coefficient, the greater the resistance force.

## 4. What are some examples of resistance force and friction coefficient in everyday life?

Examples of resistance force and friction coefficient in everyday life include the friction between car tires and the road, the resistance force of air on a moving airplane, and the friction between a pencil and paper when writing.

## 5. How do resistance force and friction coefficient affect an object's motion?

Resistance force and friction coefficient can both act to slow down or stop an object's motion. The higher the resistance force and friction coefficient, the more difficult it is for an object to move. However, they can also be used to control an object's motion, such as in the case of braking in a car.

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