question_answer

Two vectors \[\vec{A}\] and \[\vec{B}\] are in the same plane and angle between them is \[\theta \]. What is the magnitude and direction of \[\vec{A}\times \vec{B}\] ?

Answer:

                \[|\vec{A}\times \vec{B}|=AB\sin \theta \] The direction of \[\vec{A}\times \vec{B}\] is perpendicular to the plane of \[\vec{A}\] and \[\vec{B}\] and points in the same direction in which a right handed screw would advance when rotated from \[\vec{A}\] to \[\vec{B}\] .