A flywheel of mass 10 kg with a radius of gyration of 0.45 m is accelerated uniformly from 700 rpm to 1400 rpm. This takes 12 s. Ignoring friction, find the constant torque T needed.
A flywheel of mass 20 kg with a radius of gyration of 0.6 m is accelerated uniformly from rest to 1500 rpm. The driving torque is a constant 47 N·m and friction can be ignored. How long t does this take?
A uniform slender rod of mass 6.5 kg and length 2.2 m is pinned at one end and released from rest in a horizontal position. A small ball of mass 1.5 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 uniform slender rod of mass 18 kg and length 1.9 m is pinned at one end and held horizontal. It is released from rest. Use g = 9.81 m/s². Find the acceleration atip of the free end just after release.
A person stands on a frictionless turntable and holds a 5.5 kg dumbbell in each hand, 0.8 m from the axis. The person and turntable alone have a moment of inertia of 2 kg·m² about the axis. They turn at 60 rpm, then pull the dumbbells in to 0.25 m from the axis. Treat the dumbbells as point masses. Find the new speed n2 in rpm.
A person stands on a frictionless turntable and holds a 2 kg dumbbell in each hand, 0.6 m from the axis. The person and turntable alone have a moment of inertia of 2.5 kg·m² about the axis. They turn at 55 rpm, then pull the dumbbells in to 0.25 m from the axis. Treat the dumbbells as point masses. Find the new speed n2 in rpm.
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