A pendulum is made of a uniform slender rod (1 kg, 0.6 m long) pivoted at its top end O, with a solid sphere of mass 10 kg and radius 0.2 m fixed to its lower end. The centre of the sphere is 0.8 m below O. Find the mass moment of inertia IO of the pendulum about O.
A flywheel is a uniform solid disc of mass 170 kg and radius 0.4 m. It spins at 2700 rpm. Find its kinetic energy Ek in kJ.
A 5 kg block hangs from a light cord wrapped around a pulley, a uniform solid disc of mass 10.5 kg and radius 0.15 m that turns on a frictionless horizontal axle. The block is released from rest. Use g = 9.81 m/s². Find the acceleration a of the block.
A flywheel with a moment of inertia of 27 kg·m² spins at 2800 rpm. A brake applies a constant friction torque of 40 N·m. How many revolutions N does the flywheel make before it stops?
A uniform solid disc (mass 7 kg, radius 0.2 m) spins freely at 1150 rpm about a vertical frictionless shaft. A thin ring of mass 14 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 cylinder of mass 8.5 kg rolls without slipping at 5 m/s. Find its rotational kinetic energy Erot.
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