## Cross Product

Consider two vectors,AandB; we can define a new vectorCby

C=AxBRotate the first vector (

A) into the second vector (B) with the fingers of yourrighthand. Your thumb then gives the direction of the cross product,AxB.Remember,

Cisperpendicularto bothAandB.The

magnitudeof C is given by

F= qvxBRotate the first vector (

v) into the second vector (B) with the fingers of your right hand. Your thumb then gives the direction of the cross product,vxB. If the charge ispositive, this is the direction of the force. If the charge isnegative, the force is in the opposite direction. Themagnitudeof the force is given by

Return to Ch 29, Magnetic Fields(c) Doug Davis, 2002; all rights reserved