Question

A motor provides the torque necessary to keep a gear turning at constant angular velocity, overcoming friction between the gear and the axle.

The gear can be modeled as a disk, with mass 2 kg, and radius r_g = 0.2 m. The force of friction can be modeled as a single force, acting at the outer edge of the axle, at position r_a = 0.02 meters, with force of f_k = 10 N.

3 fk po 에

a) What is the magnitude of the torque the motor needs to provide, in N⋅m, to keep the gear spinning at constant angular velocity?

b) If the gear spins with angular velocity of ? = 50 rad/s, how much power does the motor use, in Watts, to keep the gear spinning?

Answer 1

=0 W = & Torque pended by motor = fk x ra constant =) 2 Ź Tonque so Nom = 10 X 0.02 =10.2 0.2 Nom lower used by metar = Tarque & angulen velocity. -0.2 x so watto = 10 watts.