# Friction of block on wall

• james2mart
In summary, the weight of the block is 64.4 N and the coefficient of static friction is 0.580. The minimum force required to prevent the block from sliding down the wall is 37.52 N, and the minimum force required to start the block moving up the wall is also 37.52 N.

#### james2mart

The weight of the block in the drawing (SEE ATTACHMENT) is 64.4 N. The coefficient of static friction between the block and the vertical wall is 0.580.

(a) What minimum force is required to prevent the block from sliding down the wall? (Hint: The static frictional force exerted on the block is directed upward, parallel to the wall.)

(b) What minimum force is required to start the block moving up the wall? (Hint: The static frictional force is now directed down the wall.)

I can't figure this out...

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a) The minimum force required to prevent the block from sliding down the wall is 37.52 N. b) The minimum force required to start the block moving up the wall is 37.52 N.

I can provide a response to this content using the principles of physics and the given information.

(a) To prevent the block from sliding down the wall, the minimum force required would be equal to the maximum static frictional force that the wall can exert on the block. This can be calculated using the formula F = μN, where F is the frictional force, μ is the coefficient of static friction, and N is the normal force exerted by the wall on the block. In this case, the normal force would be equal to the weight of the block, which is 64.4 N. Therefore, the minimum force required to prevent the block from sliding down the wall would be 0.580 x 64.4 = 37.352 N.

(b) To start the block moving up the wall, the minimum force required would be equal to the force of gravity acting on the block, which is its weight of 64.4 N, plus the minimum force required to overcome the static frictional force acting in the opposite direction. This can be calculated using the formula F = μN, where F is the frictional force, μ is the coefficient of static friction, and N is the normal force exerted by the block on the wall. In this case, the normal force would be equal to the weight of the block, which is 64.4 N. Therefore, the minimum force required to start the block moving up the wall would be 64.4 + 0.580 x 64.4 = 102.134 N.

I hope this helps to clarify the concept of friction and the minimum forces required to prevent or initiate movement in this scenario.

## What is friction and how does it affect a block on a wall?

Friction is a force that opposes motion between two surfaces in contact. When a block is in contact with a wall, friction acts to prevent the block from sliding down the wall.

## What factors affect the friction between a block and a wall?

The friction between a block and a wall depends on the type of surfaces in contact, the force pressing the surfaces together, and the roughness of the surfaces.

## How is the friction force calculated between a block and a wall?

The friction force between a block and a wall is calculated using the formula F = μN, where F is the friction force, μ is the coefficient of friction, and N is the normal force between the surfaces.

## What happens to the friction force if the block is tilted at an angle?

If the block is tilted at an angle, the normal force between the surfaces decreases, leading to a decrease in the friction force. This is because the weight of the block is no longer acting perpendicular to the wall.

## How can the friction force between a block and a wall be increased?

The friction force can be increased by increasing the force pressing the surfaces together, using rougher surfaces, or increasing the coefficient of friction between the surfaces.