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Secure https://session.masteringphysics.com/myct/itemView?assignmentProblemID-88957875 Flywheels are large, massive wheels used to store energy. They can be spun up slowly, then the wheel's energy can be released quickly to accomplish a task that demands high power. An Part A A motor spins up the flywheel with a constant torque of 57 N-m. How long does it take the flywheel to reach top speed? industrial flywheel has a 1.9 m diameter and a mass of 230 kg. Its maximum angular velocity is 1300 rpm Express your answer to two significant figures and include the appropriate units tValue Units Submit vious Answers Request Answer X Incorrect; Try Again; 26 attempts remaining Part B How much energy is stored in the flywheel? Express your answer to two significant figures and include the appropriate units EVae Units Submit Request Answer

Explanation / Answer

a) M = 230 kg, r = d / r = 1.9/2 = 0.95 m

moment of Inertia I = 1/2 M R2 = 0.5 * 230 * 0.952 = 103.8 kg.m2

w = 2 pi/60 * 1300 = 136 rad/s

angular acceleration = T / I = 57 / 103.8 = 0.549 rad/s2

t = w / apha = 136 / 0.549 = 247.6 s

b) E = 1/2 I w2 = 0.5 * 103.8 * 1362 = 9.59 * 105 J = 0.959 MJ

c) P = (E/2) / time = (959942 / 2) / 2.1 = 2.28 * 105 W = 0.228 MW

d) E/2 = 1/2 * I w2

w = sqrt [ E / I] = 96.1 rad/s

alpha = w / t = 45.7 rad/s2

torque = I apha = 4751 N.m

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