1. Communication question with vectors.

How could you use a wrench to explain why a x b = - (b x a) for any vectors a and b?

I really dont understand how to convey this in word , thanks for any help !

2. Originally Posted by nosh
How could you use a wrench to explain why a x b = - (b x a) for any vectors a and b?

I really dont understand how to convey this in word , thanks for any help !
imagine a wrench being used to tighten and/or loosen a screw. you can use the right hand rule to see how a x b differs depending on whether you are tightening or loosening the screw. one vector will be in the direction coming out of the screw head, perpendicular to the wrench, the other will go the opposite way, from the threading pointing into the hole.

hope that helps

3. thanks that does make a it more sense !

4. Originally Posted by nosh
How could you use a wrench to explain why a x b = - (b x a) for any vectors a and b?

[snip]
You go to someone who knows about cross products and threaten to hit them over the head with the wrench unless they provide the explanation.

Alternatively ..... you could read this: Vector Cross Products