# Torque = r x F

1. Feb 28, 2007

### Harmony

I saw in my reference book that T=r * F , and T=F * r is unacceptable. Why is the latter unacceptable?

2. Feb 28, 2007

### mybsaccownt

Last edited: Feb 28, 2007
3. Feb 28, 2007

### turdferguson

Also, the book probably doesnt want you to confuse units of torque (meter*newtons) and units of energy (newton*meters). Get in the habit of putting the distance first, as it will help you with the cross products

4. Feb 28, 2007

### cristo

Staff Emeritus
Huh? The (standard) unit of torque is the Newton-metre; I've never heard of it being called a metre-Newton! Besides, clearly the units Newton and metre commute.

(http://en.wikipedia.org/wiki/Newton_metre)

Last edited: Feb 28, 2007
5. Feb 28, 2007

### turdferguson

If the unit of torque is the newton-meter, that implies that its the same as a joule. By using the term "meter-newton", you can easily differentiate between torque and energy. Even though you just informed me that its not technically SI, it makes more sense to me and probably to someone just starting out