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A 20 kg sled is being pulled across a horizontal surface at a constant velocity. The pulling force has a magnitude of 80N and is directed at a angle of 30 degrees above the horizontal.

Determine the coefficient of kinetic friction.

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Final answer:

To find the coefficient of kinetic friction, we can use the equation = μk N, where is the kinetic friction, μk is the coefficient of kinetic friction, and N is the normal force.

Step-by-step explanation:

In order to determine the coefficient of kinetic friction, we can use the formula:

= μk N

Where is the kinetic friction, μk is the coefficient of kinetic friction, and N is the normal force.

In this case, the force pulling the sled is at an angle of 30 degrees above the horizontal, so we need to find the component of the force that is perpendicular to the surface.

The perpendicular component of the force is given by:

F⊥ = Fsinθ

Where F is the pulling force and θ is the angle.

Plugging in the values, we get:

F⊥ = 80N * sin(30°)

F⊥ = 40N

Since the sled is moving at a constant velocity, the force of friction is equal to the perpendicular component of the pulling force:

= F⊥ = 40N

Finally, we can rearrange the equation to solve for the coefficient of kinetic friction:

μk = / N

Since we are given the mass of the sled, we can calculate the normal force using the equation:

N = mg

Plugging in the values, we get:

N = 20kg * 9.8m/s²

N = 196N

Now we can calculate the coefficient of kinetic friction:

μk = 40N / 196N

μk ≈ 0.2041

Therefore, the coefficient of kinetic friction is approximately 0.2041.

By finding the component of the pulling force that is perpendicular to the surface, we can determine the normal force and calculate the coefficient of kinetic friction. As a result, the coefficient of kinetic friction is approximately 0.2041.

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