A flywheel of mass 20 kg with a radius of gyration of 0.45 m is accelerated uniformly from 900 rpm to 2000 rpm. The driving torque is a constant 19 N·m and friction can be ignored. How long t does this take?
A flywheel of mass 90 kg with a radius of gyration of 0.25 m is accelerated uniformly from 500 rpm to 1800 rpm. The driving torque is a constant 96 N·m and friction can be ignored. How long t does this take?
A motor brings a flywheel with a moment of inertia of 7 kg·m² from rest up to 800 rpm in 53 s. Ignoring losses, find the average power Pavg it delivers, in kW.
A shaft transmits 14.5 kW at 2000 rpm. Find the torque T in the shaft.
A uniform solid disc (mass 37 kg, radius 0.45 m) spins freely at 100 rpm about a vertical frictionless shaft. A thin ring of mass 16 kg and the same radius is dropped onto it from rest, centred on the shaft, and the two quickly spin together. How much kinetic energy ΔE is lost in the process?
A solid sphere rolls without slipping down a slope inclined at 40° to the horizontal. Use g = 9.81 m/s². Find the smallest coefficient of static friction μs that prevents it from slipping.
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