Torque of motor varies as the cube of the speed means what?

[Ahmedzica]

is this means that torque is proportional or inversely proportional to the cube of speed

the problem says

The torque of a load driven by a 385-V, Dc shunt motor varies as the cube of the speed. The current taken by the motor is 51A at a certian speed. Calculate the additional resistance to be inserted in series with the armature to reduce the speed to 50 percent of the original value. The armature circuit resistance is 0.5 ohms and the field-circuit resistance is 35 ohms


Thanks

 

[mfb]

Torque is proportional to the cube of speed.

 

[Ahmedzica]

Thanks a lot!