# Why Force Due to Friction Not in Equation of Motion?

• eurekameh
In summary, force due to friction is not included in the equation of motion because it is a non-conservative force that cannot be expressed as a simple mathematical equation. However, friction does affect the motion of an object by acting in the opposite direction and causing resistance. The coefficient of friction also plays a role in an object's motion by determining the amount of frictional force. While friction can have negative effects, it also has important uses in everyday tasks and the functioning of machines and tools.

#### eurekameh

Why is ft (the force due to the friction between the cylinder and the ramp) not included in the equation of motion?

eurekameh said:
Why is ft (the force due to the friction between the cylinder and the ramp) not included in the equation of motion?
Because the cylinder "rolls without slipping".

For this situation, is my Fx equation of motion not true then?

## 1. Why is force due to friction not included in the equation of motion?

Force due to friction is not included in the equation of motion because it is a non-conservative force. This means that the work done by friction is dependent on the path taken and not just the initial and final positions of the object. Therefore, it cannot be expressed as a simple mathematical equation like other conservative forces such as gravity or elastic force.

## 2. Does friction affect the motion of an object?

Yes, friction does affect the motion of an object. It acts in the opposite direction of the object's motion, slowing it down or bringing it to a stop. Friction also causes objects to move in a circular motion when traveling on a curved surface.

## 3. Why is friction considered a resistance force?

Friction is considered a resistance force because it opposes the motion of an object. It acts in the opposite direction of the object's motion, causing it to slow down or come to a stop. This resistance force is caused by the interaction between the surfaces of two objects.

## 4. How does the coefficient of friction affect an object's motion?

The coefficient of friction is a measure of the frictional force between two surfaces. It affects an object's motion by determining the amount of frictional force acting on the object. A higher coefficient of friction means a greater resistance force, and therefore, the object will experience a slower motion or come to a stop faster.

## 5. Is friction always a bad thing?

No, friction is not always a bad thing. While it does oppose motion and can cause wear and tear on surfaces, it also has many important uses. Friction allows us to walk, drive, and grip objects. It is also important in the functioning of machines and tools. Without friction, many everyday tasks would be difficult or impossible to accomplish.