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Operations on Vectors. Vector Addition. There are two methods to add vectors u and v Tip to tail (triangle method ) Parallelogram Properties of Addition u + v = v + u (u + v) + w = u + (v + w) u + 0 = u u + (-u) = 0. u. v. Tip to Tail Method. u. v.
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Vector Addition • There are twomethods to addvectorsu and v • Tip to tail (triangle method) • Parallelogram • Properties of Addition • u + v = v + u • (u + v) + w = u + (v + w) • u + 0 = u • u + (-u) = 0 u v
VectorSubtraction • Property of Subtraction • u - v = u + (-v)
Calculating the norm and direction of resultantvectors • PythagoreanTheorem • Right angle triangles only! • Sine Law • Cosine Law
Examples Tony walks 5m West and 7m North. Determine the length and angle of the resultant motion. c2 = a2 + b2 c2 = 52 + 72 R c2 = 74 7m c = 8.6 m θ Tanθ= 7/5 =1.4 5m θ= 54.5° 8.6m W 54.5° N
Example A bear, searching for food wanders 35 meters east then 20 meters north. Frustrated, he wanders another 12 meters west then 6 meters south. Calculate the bear's displacement. 23 m, E - = 12 m, W - = 14 m, N 6 m, S 20 m, N 14 m, N 35 m, E R q 23 m, E The Final Answer: 26.93 m, 31.3 degrees NORTH of EAST
Example Tommy travels 5 km North and thendecides to travel 3.9km [W 5°N]. Determine the vectorthatrepresents the distance and orientation fromhisstarting point.
Example • Determine the resultantvector of u- v 3 cm u 3 cm 60° 60° R 50° 50° v 3 cm 3 cm 50°
Chasles Relation • If A, B and C are three points in a cartesian plane, then: AB + BC = AC B A C
Example • Simplifyeach expression: • CD + DE + EF • AB – FB • -CD + CE - FE
Multiplication of a Vector by a Scalar The product of a non-zerovector and a scalaris a vector au if a > 0, u and au same direction if a < 0, u and au opposite directions • Properties of Multiplication • a(bu) = ab(u) • u x 1 = u • a(u + v) = au + av
Algebraic Vectors Operations between Algebraic Vectors Given vectors u = (a,b) and v = (c,d) u + v = (a + c, b + d) u - v = (a - c, b - d) ku = (ka,kb) where k is any real number (scalar)
Example Consider the followingvectors: u = (8,4) v = (2,1) w = (6,-2) Calculate a) u + v b) w – v c) 3u – v + 2w d) ll 5w – ull
Example 1. Drawvectorv if (- 4v)isrepresentedbelow. 2. Reduce: -2u + v – 6v + 3u