# Quick friction concept question

• jcpwn2004
In summary, the question is which angle of force causes the most or least amount of friction when pulling a box across a rough horizontal surface. The solution involves resolving the forces into horizontal and vertical components and understanding that pulling below horizontal increases the normal force and therefore friction, while pulling above horizontal decreases the normal force and reduces friction. The equation for force of friction is mu multiplied by the normal force.
jcpwn2004

## Homework Statement

A box is pulled across a rough horizontal surface with force F. Each time the box moves a distance D, howeveer the angle of F varies. Which angle causes the most/least amount of friction. An angle above/below/horizontal to the surface.

## The Attempt at a Solution

I know that the least friction is caused by a force above horizontal and the most is caused by a force below horizontal but I have no clue how to explain it using physics.

Try imagining the forces resolved into horizontal and vertical components. Does that help?

2. Homework Equations ,

Force of Friction = mu*Normal ForceSo if u are pulling bellow the horiziontal, u are pusing the box into the ground, thus increasing the normal force => increasing friction.

If you pull above horizontal, then u are pulling up the box => less Normal force => less friction

make sense?

ZPOWER

## 1. What is friction?

Friction is a force that resists the motion of objects when they come in contact with each other.

## 2. How does friction affect motion?

Friction can either slow down or stop the motion of an object, or it can cause an object to move in a different direction.

## 3. What factors affect the amount of friction?

The amount of friction between two surfaces is affected by the type of surface, the force pressing the surfaces together, and the roughness or smoothness of the surfaces.

## 4. What are the different types of friction?

There are three types of friction: static, sliding, and rolling. Static friction occurs when two surfaces are not moving relative to each other, sliding friction occurs when two surfaces are moving relative to each other, and rolling friction occurs when a round object rolls on a surface.

## 5. How can friction be reduced?

Friction can be reduced by using lubricants such as oil or grease, using smoother or more slippery surfaces, or by reducing the force or weight pressing the surfaces together.

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