if you use a horizontal force of 30 N to slide a 12 kg wooden crate across a floor at a constant velocity, what is the coefficient of kinetic friction between the crate and the floor?
Wb = M*g = 12 * 9.8 = 117.6 N. = Normal
force, Fn.
Fx-Fk = M*a.
Fx-Fk = M*0 = 0.
Fk = Fx = 30 N.
Fk = u*Fn.
u = Fk/Fn = 30/117.6 = 0.255.
Note: Since the velocity is constant, the acceleration is zero.
A 200kg crate is pushed horizontally with a force of Fa= 700N if the coefficient of friction is right to left muk=0.2 calculate the acceleration of the crate?
To find the coefficient of kinetic friction between the crate and the floor, we can use the following formula:
frictional force = coefficient of kinetic friction × normal force
In this case, the crate is being pushed horizontally with a force of 30 N. Since the crate is moving at a constant velocity, we know that the frictional force is equal to the applied force, which is 30 N.
The normal force is equal to the weight of the crate, which can be calculated using the formula:
normal force = mass × acceleration due to gravity
Given that the mass of the crate is 12 kg and the acceleration due to gravity is approximately 9.8 m/s², we can calculate the normal force:
normal force = 12 kg × 9.8 m/s² = 117.6 N
Now, we can substitute the values into the formula to solve for the coefficient of kinetic friction:
30 N = coefficient of kinetic friction × 117.6 N
Divide both sides of the equation by 117.6 N:
coefficient of kinetic friction = 30 N / 117.6 N
Simplifying this calculation, we find:
coefficient of kinetic friction ≈ 0.255
Therefore, the coefficient of kinetic friction between the crate and the floor is approximately 0.255.
To find the coefficient of kinetic friction between the crate and the floor, we need to use Newton's second law of motion and the equation for kinetic friction.
Step 1: Determine the force of kinetic friction (Fk)
The force exerted to slide the crate is equal to the force of kinetic friction. In this case, the applied force is 30 N.
Step 2: Calculate the acceleration (a)
Since the crate is moving at a constant velocity, the acceleration is zero. This means the net force acting on the crate is also zero.
Step 3: Apply Newton's second law of motion
Newton's second law states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the net force is the force of kinetic friction (Fk). The equation is given as:
Fnet = m * a
Since the acceleration (a) is zero, the equation simplifies to:
Fk = m * 0
Fk = 0
Therefore, the force of kinetic friction (Fk) is zero.
Step 4: Calculate the coefficient of kinetic friction (μk)
The coefficient of kinetic friction (μk) is defined as the ratio of the force of kinetic friction to the normal force (Fn) acting on the object.
The equation for kinetic friction is:
Fk = μk * Fn
Since Fk is zero, we have:
0 = μk * Fn
Since the crate is on a horizontal floor, the normal force (Fn) is equal to the weight of the crate (mg). Therefore:
0 = μk * mg
We can rearrange the equation to solve for the coefficient of kinetic friction (μk):
μk = 0 / mg
μk = 0
Therefore, the coefficient of kinetic friction between the crate and the floor is 0.