The rotor of an electric motor has an angular velocity of 3600 rpm when the load and power are cut off. The 120-lb rotor, which has a centroidal radius of gyration of 9 in., then coasts to rest. Knowing that kinetic friction results in a couple of magnitude 2.5 lb·ft exerted on the rotor, determine the number of revolutions that the rotor executes before coming to rest.

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Q: The rotor of an electric motor has an angular velocity of 3600 rpm when the load and power are cut…

A: W=121 lb ∑MG=2.5lb.ft k=9in=0.75 ft N=3600rpm We need to find The number of revolutions

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Q: The uniform rod AB of weight W is released from rest when β = 70°. Assuming that the friction force…

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Q: A driver starts his car with the door on the passenger’s side wide open ( _ θ = 0). The 100-lb door…

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Q: The 200-mm radius brake drum is attached to a larger flywheel that is not shown. The total mass…

A: calculated the number of revolutions executed by the flywheel before it comes to rest.

Q: The mechanism shown is one of two identical mechanisms attached to the two sides of a 200-lb uniform…

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Q: A 6000-lb flywheel requires 1500 revolutions to coast to rest from an angular velocity of 300 rpm.…

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Q: The 80-mm-radius gear shown has a mass of 5 kg and a centroidal radius of gyration of 60 mm. The…

A: Given: The radius of the gear is r=80 mm=0.08 m. The length of AB is L= 320 mm=0.320 m. The mass of…

Q: The mechanism shown is one of two identical mechanisms attached to the two sides of a 200-lb uniform…

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Q: Disk A has a mass of 6 kg and an initial angular velocity of 360 rpm clockwise; disk B has a mass of…

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Q: Problem (4) An 8-kg gear with a radius of 80 mm has a centroidal radius of gyration of 50 mm. A 5-kg…

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Conservation of Energy

In physics, the rule of the conservation of energy states that energy doesn’t disappear from the atmosphere; instead, it changes its form from one type to another. Energy is one of the most important physical quantities in nature, and it cannot be created or destroyed — only transformed.