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Rotational Dynamics


Problems

Problem :

A single particle of mass 1 kg, starting from rest, experiences a torque that causes it to accelerate in a circular path of radius 2 m, completing a full revolution in 1 second. What is the work done by the torque over this full revolution?


Problem :

What is the kinetic energy of a single particle of mass 2 kg rotating around a circle of radius 4 m with an angular velocity of 3 rad/s?


Problem :

Often revolving doors have a built in resistance mechanism to keep the door from rotating dangerously quickly. A man pushing on a door of 100 kg at a distance of 1 meter from its center counteracts the resistance mechanism, keeping the door moving at a constant angular velocity if he pushes with a force of 40 N. If the door moves at a constant angular velocity of 5 rad/s, what is the power output of the man over this time?