How can there be work due to torque?

[henry3369]

Homework Statement

I'm doing rotational problems and I'm having a hard time understanding how work done by torque is possible.

Homework Equations

The Attempt at a Solution

The equation is W = TΔΘ. Torque points along the axis of rotation and ΔΘ always points along the rotational motion of the object. These two are perpendicular to each other so how can there be work done? I know in linear motion, if the force is perpendicular to the motion of the object, there is no work done. Do these rules not apply to work done on rotating object?

 

[CWatters]

I think this is the maths you want but I'm very rusty..

http://en.wikipedia.org/wiki/Work_(physics)#Torque_and_rotation.

 

[Jobrag]

Go back to basics, work is force times distance moved, now look at where the force is in torque and how far it moves when a shaft is spinning.