# Question about frictional and normal force

## Homework Statement

Okay so there is a wall that has a mass of 150 kg and I am pushing it but the wall does not move. The coefficient of friction is 2 and I am trying to find the frictional force using the frictional force formula. Although, I need the normal force in which I am using to push the wall but don't know how to find the normal force.

Fr = (mu)(Fn)

haruspex
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## Homework Statement

Okay so there is a wall that has a mass of 150 kg and I am pushing it but the wall does not move. The coefficient of friction is 2 and I am trying to find the frictional force using the frictional force formula. Although, I need the normal force in which I am using to push the wall but don't know how to find the normal force.

Fr = (mu)(Fn)

## The Attempt at a Solution

You need to describe the set up better. Frictional force between what two objects - you and the wall?
Friction acts parallel to the surfaces in contact. If there is no movement and no other forces in that direction then the frictional force will be zero, regardless of the coefficient. The static frictional force is only as large as it needs to be to prevent relative motion. The correct equation is |Fr| <= mu |Fn|.