Friction help. AP Physics C student

In summary, a 2.5 kg block is initially at rest on a horizontal surface. A horizontal force of magnitude F = 6.0 N and a vertical force of magnitude P are applied to the block. The coefficients of friction for the block and surface are μ_s = 0.40 and μ_k = 0.25. The magnitude of the frictional force acting on the block can be determined by using the formula Ff=μFn and calculating the normal force Fn=-mg. The magnitude of P is given as 8.0 N, 10 N, and 12 N in separate scenarios.For further assistance, one should show some attempt at a solution and consider all forces in the y direction to calculate
  • #1
bobAllan
1
0
1. A 2.5 kg block is initially at rest on a horizontal surface. A horizontal force of magnitude F = 6.0 N and a vertical force of magnitude P are then applied to the block. The coefficients of friction for the block and surface are μ_s = 0.40 and μ_k = 0.25. Determine the magnitude of the frictional force acting on the block if ...
a) ...the magnitude of P is 8.0 N.

b) ...the magnitude of P is 10 N.

c) ...the magnitude of P is 12 N.


2

Fn=-mg
Ff=μFn



3.
honestly- not sure where to get started. i have the answers in the back of the book, but would really like to understand this and how to find hte solution
 
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  • #2
Please show some attempt at a solution for further assistance. You listed a couple of relevant equations, but neither is quite correct. Look at all forces in the y direction to calculate the normal force, and look up again the formula for friction.
 

FAQ: Friction help. AP Physics C student

What is friction?

Friction is a force that resists the movement of objects in contact with each other. It is caused by the interactions between the surfaces of the objects and can act in the opposite direction of an applied force.

How does friction affect objects?

Friction can either help or hinder the motion of objects. It can help by providing traction for objects to grip and move, such as a car's tires on the road. However, it can also hinder motion by causing resistance and slowing down an object's movement.

What factors affect the amount of friction?

The amount of friction between two surfaces depends on the type of materials, the force pressing the surfaces together, and the roughness of the surfaces. Smooth surfaces and light forces typically result in less friction, while rough surfaces and heavier forces result in more friction.

How is friction related to Newton's laws of motion?

Friction is closely related to Newton's laws of motion, particularly the first law which states that an object at rest will remain at rest unless acted upon by an external force. Friction is also a reaction force that opposes the applied force, as described in Newton's third law.

How can friction be reduced or increased?

Friction can be reduced by using lubricants or smoother surfaces, and by applying less force. It can be increased by using rougher surfaces or increasing the force between the surfaces. Additionally, friction can be reduced through the use of wheels or rollers, which allow for smoother movement.

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