CHAPTER 11. VECTORS 11.8
Step 4 : Quote the resultant
The resultant displacement is therefore 18,5 kmon a bearing of 062,8◦.Exercise 11 - 4
- A frog is trying to cross a river. It swims at 3 m·s−^1 in a northerly directiontowards the opposite
bank. The water is flowing in a westerly direction at 5 m·s−^1. Find the frog’s resultant velocity
by using appropriate calculations. Include a rough sketch of the situation in your answer. - Sandra walks to the shop by walking 500 m Northwest and then 400 mN 30◦E. Determine her
resultant displacement by doing appropriate calculations.
More practice video solutions or help at http://www.everythingscience.co.za(1.) 00n8 (2.) 00n911.8 Components of Vectors
In the discussion of vector addition we saw thata number of vectors acting together can be combined
to give a single vector (the resultant). In much thesame way a single vector can be broken down into a
number of vectors whichwhen added give that original vector. These vectors which sum to the original
are called components of the original vector. The process of breaking avector into its components is
called resolving into components.
While summing a givenset of vectors gives justone answer (the resultant), a single vector canbe
resolved into infinitelymany sets of components. In the diagrams below the same black vector is
resolved into different pairs of components. These components are shown as dashed lines. When
added together the dashed vectors give the original black vector (i.e. theoriginal vector is the resultant
of its components).
In practise it is most useful to resolve a vector intocomponents which are at right angles to one another,
usually horizontal and vertical.