# Concept of torque direction

1. Apr 18, 2012

### zealous131

Hi, I want to clear my concept about the direction of torque for a sin curve. Assume the torque can be represented by a sin wave (T=sinx, where x is from 0 to 2π and it starts from the origin(0,0) with an amplitude of 1.

My understanding of the torque direction is as follows (assumuing clockwise torqe to be positive):

1- from 0 to the first maxima (0≤T≤1), torque was increasing and its direction was positive.
2- from first maxima, the direciton of the torque becomes anticlockwise until it reashces the first minima. (i.e. for 1≤T≤-1 torque is anti-clockwise)
3- From the first minima until the zero crossing, the direction of the torque becomes clockwise again.i.e. (-1≤T≤1, torque is clockwise again).

Please comment if I am right or wrong and suggest me the true direction sense for this particular case.

2. Apr 18, 2012

### Bob S

First of all, sin(x) is unitless, while torque has units of length x force; e.g., meter-Newtons.
Torque is positive; 0 < x < π
Torque is negative; π < x < 2π
The right hand rule determines direction of torque.

3. Apr 18, 2012

### zealous131

Thanks Bob!! Its clear now, really appreciate your help!