A scalar is a quantity in math or science whose 1e: age, volume, area, speed, mass, distance and temperature A vector on the other hand has can be specied by just a number. Ie: weight, velocity, force, friction, displacement Vectors are represented by a magnitude and the direction is indicated by the arrowhead. where the length of the line segment is the The vectors above ( AB and BA ) are called Their magnitudes are but their directions are of each other. .. AB = -BA and - AB = BA Two vectors are equal (equivalent) to each other if and only if (iff); They are parallel to each other, and the direction is the same They are of equal magnitude (length) Eg.1: Rhombus ABCD is drawn and its two diagonals AC and BD are drawn as shown. Name vectors equal (equivalent) to each of the following. B a) AB b) DA C EB d) AE A E C DEg.2: Draw a vector representing a velocity of 23 m/s on a bearing of 225. Solution: scale: 1 cm: 10 m/s N: 2.3 cm 225 When adding vectors, we can use either; 1) ii) Triangle Law ofAddition , '1 c ' 1 i? _> _, , a + b 2 . ' b + ' A\". --> 'B a In the diagram the sum of the vectors E and 3, 71' + E, is found by translating the tail of vector 19 to the head of vector If. This could also have been done by translating 3 so that its tail was at the head of b. In either case. the sum of the vectors 5 and b is AC. > > The Sum of a and b sometimes referred to as the is the vector with the tail at the tail of the rst vector and head at the end of the second vector. Vector addition is commutative because if we found the sum of b and a the resultant would be equivalent since it is parallel to and of same length and direction