Respuesta :

A motor spins upward the flywheel with a persistent torque of 50N⋅m.

What time does it take the flywheel to get to the top speed?
From the equation: 
Tj = J*dω/dt 


you can get the two equations: 
Δt1= J1*Δω/Tj = 240*125.66/50 = 603.17 sec 
Δt2= J2*Δω/Tj = 120*125.66/50 = 301.58 sec