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A clay cylinder of radius 20 cm on a potter’s wheel spins at a constant rate of 10 rev/s. The potter applies a force of 10 N to the clay with his hands where the coefficient of friction is 0.1 between his hands and the clay. What is the power that the potter has to deliver to the wheel to keep it rotating at this constant rate?

a) 628 W
b) 785 W
c) 942 W
d) 1099 W

User Kimbebot
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1 Answer

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Final answer:

To find the power that the potter has to deliver to the wheel, calculate the torque exerted by the potter's hands on the clay cylinder and use the formula P = τ * ω. The power is approximately 126 W.

Step-by-step explanation:

To find the power that the potter has to deliver to the wheel, we need to calculate the torque exerted by the potter's hands on the clay cylinder.

The formula for torque is τ = F * r * sin(θ), where F is the force applied, r is the radius of the cylinder, and θ is the angle between the force and the lever arm (radius).

In this case, the force applied by the potter is 10 N and the radius of the cylinder is 20 cm (0.2 m). The angle between the force and the lever arm is 90 degrees, so sin(θ) = 1. Substituting these values into the formula gives us τ = 10 N * 0.2 m * 1 = 2 Nˤm.

The power is then given by the formula P = τ * ω, where P is power, τ is torque, and ω is angular velocity. The angular velocity is given as 10 rev/s, which is equivalent to 20π rad/s. Substituting the values into the formula gives us P = 2 Nˤm * 20π rad/s = 40π Nˤm/s = 125.66 W.

Therefore, the power that the potter has to deliver to the wheel to keep it rotating at a constant rate is approximately 126 W.

User Wjbeau
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