A disk is rotating at 50rps (revolution per second) about its fixed axis (delta) with respect to which its moment of inertia is J= 2×10^-2 kg.m^2 A braking couple of moment -0.5N.m is applied to the disk (the sense of rotation of the disk is taken as positive ). The disk will stop after a duration t equals to what?

Question

A disk is rotating at 50rps (revolution per second) about its fixed axis (delta) with respect to which its moment of inertia is J= 2×10^-2 kg.m^2 A braking couple of moment -0.5N.m is applied to the disk (the sense of rotation of the disk is taken as positive ). The disk will stop after a duration t equals to what?

bobpursley · Answer

wf=wi+alpha*t but alpha (acceleration)=force/I so solve for time t. 2PI*0=2PI*50-.5/2E-2 * t