Friction is the force that opposes the relative motion of tangible textures, fluid layers, and material elements sliding against each other. Friction is one of the fundamental physics forces in nature, and understanding how it works is key to understanding many natural and artificial phenomena. We made this calculator that helps you calculate the friction force.

If you want to find the force of an object, you can use our Force calculator.

Friction definition

Friction arises from the contact between two surfaces, which are usually in contact only at their points of contact. Friction is also a term used to describe the resistance of one object to another. For example, you can find friction in the context of the ground being difficult to walk on because of the sand or rocks. The sand or rocks are causing the person to have to push down harder on their feet to move. 

How to find the frictional force

You can find frictional force easily using our calculator. It is proportional to the force applied to the surface and the normal force. The coefficient of friction, often denoted by the Greek letter mu, is the ratio of the frictional force to the normal force. The coefficient of friction is equivalent to the balance of the two coefficients of static friction.

If you are trying to find the frictional force, you can use the formula below:

F = \mu \cdot N

Where F is the frictional force, μ is the coefficient of friction, and N is the normal force. The coefficient of friction is a percentage that measures the magnitude of the frictional force between two surfaces. A high coefficient of friction means that there is a high frictional force between two surfaces.

Friction Force - graph
Frictional Force – graph

Force of friction equation

Newton’s Second Law of Motion describes that the net force operating on an object equals its mass multiplied by its acceleration. When a thing is at rest, the only force working on it is the force of friction. The influence of friction is dependent on the two surfaces in contact and the amount of pressure being applied. When an object is moving, the net force acting on it is the force of friction and gravity. The net force is equivalent to the object’s mass multiplied by its acceleration.

If you need to find the gravity force of an object, you can use our Gravitational force calculator.

You can use the equation in the case of two surfaces, but you can apply it to any number of surfaces. You can often use it in cases where there is not a lot of friction. The coefficient of friction is an empirical number that changes based on the type of surface, the temperature, and the relative velocity.

Types of frictional force

In literature, you can find three main types of frictional force: static, kinetic, and sliding. The static frictional force is the force that opposes the motion of an object when the object is not moving. On the other way, a kinetic frictional force is a force that opposes the motion of an object when the thing is moving. When we talk about sliding friction, it is the force that resists movement when two surfaces are sliding against each other.

Frictional force examples

If you are studying the physics of friction, this rubber material is perfect for you. You can use it to perform experiments on friction in your lab or at home. It is made of high-quality rubber that is durable and long-lasting.

You can also use our calculator to make sure you have calculated the friction force correctly.

Here are two examples to better understand friction force:

When a bus travels on a wet road, the tire slides over the surface of the road. This motion is made possible by a lubricating film of water between the tire and the road. The water on the road surface acts as a lubricant, reducing the frictional force on the tire.

A typical example of the coefficient of friction is between two blocks of wood on a table. The coefficient of friction is more significant for rubber on a glass table than for wood on a wood table.

Static friction vs. Kinetic friction

Static friction is one type of friction force that resists the relative motion of two surfaces in contact with each other. It is independent of the direction of the applied force but depends on the surfaces in contact. 

Kinetic friction is one type of friction force that resists the relative motion of two surfaces in contact with each other. It relies on the direction of the applied force but is independent of the surfaces in contact.

FAQ?

1. Is friction a contact force?

The answer is yes. It is a contact force that resists the relative motion of two surfaces in contact. 

2. Friction is a force in which two objects?

It is a force between two objects that are in contact with each other, tend to move in opposite directions.

3. How to calculate frictional force?

The formula for calculating the force of friction is F = μN, where F is the friction force, μ is the coefficient of friction, and N is the normal force. 

4. How to calculate the coefficient of friction?

To find the coefficient of friction, you can use the formula: μ=μs*μn.
Where μs is the static coefficient of friction and μn is the kinetic coefficient of friction.
If you need help, check our calculator!

5. How to calculate friction force without coefficient?

You can calculate a force without the coefficient of friction if it is not known. You can do it by using the equation F=μN, where F is the magnitude of the force, μ is the coefficient of friction, and N is the normal force.
The unit of measurement of the coefficient of friction is number one (1). The coefficient of friction can be determined using a slope with variable inclination by choosing the angle α at which the body starts to move down the slope, where μ = tan α.

6. How to calculate static friction?

First, you must know that static friction is the force that resists the motion of an object when it is at rest. It is also called kinetic friction. The equation for calculating static friction is Fs = μs*N. 
Fs is the force of static friction, μs is the coefficient of static friction, and N is the normal force.

7. How to calculate work done by friction?

The work done by friction is equal to the loss of kinetic energy. A general definition of work is the amount of energy transferred to an object by the action of a force. In the case of friction, the amount of work done by friction is the energy transferred to an entity from a force. The force of friction is then calculated by multiplying the net force of friction by the object’s weight.