360 likes | 468 Views
This session delves into the concept of the vector (cross) product, exploring its geometrical representation and key properties such as non-commutativity and distributivity over addition. Learn to express the vector product in terms of components and discover its applications, including calculating the moment of a force about a point or a line. The session will feature exercises on finding unit vectors perpendicular to planes, determining areas of parallelograms and triangles formed by vectors, and using vector methods to solve geometrical problems.
E N D
Session Vectors -2
Session Objectives • Vector (or Cross) Product • Geometrical Representation • Properties of Vector Product • Vector Product in Terms of Components • Applications: Vector Moment of a Force about a Point, about a Line • Class Exercise
O Vector (or Cross) Product
1. Vector product is not commutative 2. Vector product is distributive over vector addition Properties of Vector Product
Find a unit vector perpendicular to the plane containing the vectors . Example –1
Solution: The vector perpendicular to the plane ABC is . Example –2
Find the area of a parallelogram determined by the vectors Example -6
Example -7 Find the area of the triangle formed by the points A(1, 1, 2), B(2, 3, 5) and C(1, 5, 5).
O P Moment of Force About a Point
The moment of the force acting through B about the point A is given by Solution Cont.
The moment of the force about the given line is Solution Cont.
In a triangle ABC, prove by vector method that: Geometrical Problem Example -10 Solution: By triangle law of vector addition
Solution Cont. From (i) and (ii), we get