Kinetic Friction Homework: Solve for Acceleration of 880 N Crate

In summary, kinetic friction is the force that opposes the movement of an object when it is in contact with another surface. It is caused by the microscopic irregularities of the two surfaces rubbing against each other. It differs from static friction, which prevents an object from moving when it is at rest, and is generally weaker. To calculate the acceleration of an object with a given kinetic friction value, you can use the formula a = (F - F<sub>k</sub>) / m, where F is the applied force, F<sub>k</sub> is the kinetic friction force, and m is the mass of the object. In order to solve for the acceleration, you will need the weight of the crate, the kinetic friction force,
  • #1
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Homework Statement


A 880 N crate is being pulled across a level floor by a force F of 395 N at an angle of 25° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate.


Homework Equations


not quite sure?? was absent


The Attempt at a Solution


dont know where to begin
 
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  • #2
wow nevermind solved it...

found Fn first using the N of the crate and sin of the applied force, then i plugged that into

ma=uFn and found m by dividing 880 by 9.8 then just solved for a
 
  • #3


I would suggest starting by breaking down the problem into smaller components and identifying any relevant equations that can be used to solve for the acceleration. In this case, we are dealing with a crate being pulled at an angle with a known force and coefficient of kinetic friction.

One possible approach would be to use Newton's Second Law, which states that the net force acting on an object is equal to its mass multiplied by its acceleration. In this case, the net force is the horizontal component of the pulling force minus the force of friction:

Fnet = Fpull - Ffriction

We can calculate the horizontal component of the pulling force by using trigonometry: Fpull = 395 N * cos(25°) = 355.54 N.

The force of friction can be calculated using the coefficient of kinetic friction and the normal force, which is equal to the weight of the crate (880 N) in this case:

Ffriction = μ * N = 0.25 * 880 N = 220 N

Plugging these values into the equation for net force, we get:

Fnet = 355.54 N - 220 N = 135.54 N

Now, we can use Newton's Second Law to solve for the acceleration:

Fnet = ma

135.54 N = (880 N) * a

a = 135.54 N / 880 N = 0.154 m/s^2

Therefore, the magnitude of the acceleration of the crate is 0.154 m/s^2.
 

1. What is kinetic friction?

Kinetic friction is the force that opposes the movement of an object when it is in contact with another surface. It is caused by the microscopic irregularities of the two surfaces rubbing against each other.

2. How is kinetic friction different from static friction?

Static friction is the force that prevents an object from moving when it is at rest, while kinetic friction is the force that opposes the movement of an object in motion. Kinetic friction is generally weaker than static friction.

3. How do I calculate the acceleration of a crate with a given kinetic friction value?

To calculate the acceleration of an object, you can use the formula a = (F - Fk) / m, where F is the applied force, Fk is the kinetic friction force, and m is the mass of the object. In this case, F would be the weight of the crate, which is 880 N.

4. What information do I need to solve for the acceleration of a crate with a given kinetic friction value?

To solve for the acceleration, you will need the weight of the crate, the kinetic friction force, and the mass of the crate. The kinetic friction force can be calculated by multiplying the coefficient of kinetic friction with the normal force (which is equal to the weight of the crate).

5. How does the coefficient of kinetic friction affect the acceleration of a crate?

The coefficient of kinetic friction is a measure of the roughness of the surfaces in contact. The higher the coefficient, the rougher the surfaces are, and the stronger the kinetic friction force will be. This means that a higher coefficient of kinetic friction will result in a lower acceleration of the crate, as more force is needed to overcome the friction force.

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