A flywheel of mass 70 kg with a radius of gyration of 0.1 m is accelerated uniformly from rest to 1100 rpm. The driving torque is a constant 3 N·m and friction can be ignored. How long t does this take?
A flywheel of mass 220 kg has a radius of gyration of 0.35 m about its axis. It spins at 2700 rpm. Find its kinetic energy Ek in kJ.
A uniform slender rod of mass 3 kg and length 1.2 m is pinned at one end and released from rest in a horizontal position. A small ball of mass 5 kg is fixed to its free end. Ignore friction and use g = 9.81 m/s². Find the speed v of the free end as the rod swings through the vertical position.
A motor brings a flywheel with a moment of inertia of 39.5 kg·m² from rest up to 2800 rpm in 59 s. Ignoring losses, find the average power Pavg it delivers, in kW.
A uniform solid disc (mass 6 kg, radius 0.2 m) spins freely at 150 rpm about a vertical frictionless shaft. A thin ring of mass 1 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 of mass 13 kg rolls without slipping at 1.5 m/s. What percentage p of its total kinetic energy is rotational?
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