AC motors starting torque

[sonic seven]

Hi, question is for my industrial electronics course. A 4-pole 460v motor has a starting torque of 200lb/ft. Predict it's starting torque if EL is reduced by 10%.(EL=line voltage). Should this be solved as a proportion? thank you.

 

[ecerfoglio]

If EL is reduced by 10% the starting torque will be reduced... But not by 10 %

You may think the torque as power divided by speed ....

You may think power as voltage times current ....

You may think current as voltage divided by impedance ...

With theese hints you should be able to find the answer by yourself