Amotor spins up the flywheel with a constant torque of 50 n⋅m. how long does it take the flywheel to reach top speed?

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 

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s