EXAMPLE 6 :If   P  º  (8,2)  and  Q  º  (-3,4),   Find  

Solution: P º (8,2) and Q º (-3,4)

EXAMPLE 7 : A force of 30 N and a force of 10 N act on an object at an angle of 50⁰ with respect to each other. What is the magnitude of the resultant force and what angle does the resultant force form with the force of 30N?

Solution

Let F₁ be the first Force , | F₁ | = 30N

Let F₂ be the second force, | F₂ | = 10N

Let the angle between the two forces be a, and q be the angle between the force F₁ and the  resultant  force F.     Given that a = 50⁰

Using the cosine Law, F²= F₁ ² + F₂ ² - 2F₁ . F₂ cos 130⁰

Thus the magnitude of the resultant is |F| = 37.225N and the resultant force F makes an angle of 11.88⁰ with the force of 30N.

Index

7.1 Scalers & Vectors
7.2 Algebra of Vectors
7.3 Representation of a vector in a plane
7.4 Dotor Scalar product
7.5 Polar Co-ordinates
Supplementary Problems

Chapter 8