A flywheel of mass 70 kg with a radius of gyration of 0.15 m is accelerated uniformly from 500 rpm to 900 rpm. The driving torque is a constant 2.4 N·m and friction can be ignored. How long t does this take?
A flywheel of mass 240 kg has a radius of gyration of 0.3 m about its axis. It spins at 2100 rpm. Find its kinetic energy Ek in kJ.
A uniform slender rod of mass 9.5 kg and length 2 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 uniform slender rod of mass 2.5 kg and length 1.9 m is pinned at one end and released from rest in a horizontal position. A small ball of mass 2 kg is fixed to its free end. Ignore friction and use g = 9.81 m/s². Find the angular velocity ω of the rod as it swings through the vertical position.
A person stands on a frictionless turntable and holds a 3.5 kg dumbbell in each hand, 0.65 m from the axis. The person and turntable alone have a moment of inertia of 4.5 kg·m² about the axis. They turn at 30 rpm, then pull the dumbbells in to 0.2 m from the axis. Treat the dumbbells as point masses. Find the new speed n2 in rpm.
A thin hoop rolls without slipping down a slope inclined at 15° to the horizontal. Use g = 9.81 m/s². It starts from rest. How long t does it take to roll 3 m down the slope?
Full step-by-step solutions: practise this topic on examproblems.com.