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Suppose the wheel (R = 20.0 cm, M = 2.90 kg) is rotated at a constant rate so that the mass m = 0.785 kg has an upward speed of 3.65 m/s when it reaches a point P. At that moment, the wheel is released to rotate on its own. It starts slowing down and eventually reverses its direction due to the downward tension of the cord. What is the maximum height, h (in m), the mass will rise above the point P

User Jack Ryan
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Final answer:

Using conservation of energy principles, the mass attached to the wheel will rise to a maximum height of approximately 0.681 meters above point P when the wheel is released.

Step-by-step explanation:

The question concerns a physical scenario where a wheel of radius 20.0 cm and mass 2.90 kg is rotating at a constant rate, raising a mass m = 0.785 kg until it reaches a point P with an upward speed of 3.65 m/s. Once the wheel is released, it starts to slow down, eventually reversing its direction due to the downward tension of the cord. To find the maximum height h the mass will rise above point P, we can use the principle of conservation of energy; specifically, the transformation of kinetic energy into gravitational potential energy.

At the moment when the wheel is released, the kinetic energy can be expressed as K.E. = 0.5 * m * v^2, where m is the mass of the weight and v is its speed at point P. As the wheel slows down, this kinetic energy is converted to gravitational potential energy, which is given by P.E. = m * g * h, with g being the acceleration due to gravity (9.8 m/s^2), and h the height above point P.

Equating the kinetic energy at point P with the potential energy at the maximum height, we get:

0.5 * m * v^2 = m * g * h

Solving for h, we find:

h = (0.5 * v^2) / g

Inserting the given values:

h = (0.5 * (3.65 m/s)^2) / (9.8 m/s^2)

Calculating gives us:

h = 0.681 m

Therefore, the maximum height the mass m will rise above the point P is approximately 0.681 meters.

User Shadowwalker
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