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Explore vector visualization techniques, from latitude and longitude to altitude, to enhance precision in navigating space. Learn to decompose and add vectors while mastering scalar and vector products. Includes practice exercises.
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Ch.3 Vectors Visualizing Vector fields
2-D Vectors Latitude + Longitude gives location
3-D Vectors Latitude + Longitude + Altitude more precise
To go from A to B Need Origin (Charlottesville), Magnitude (70.12 miles), Direction (bear SouthEast)
To go from A to B 2D Map
To go from A to B Decomposing a vector OR Adding several vectors
Adding Vectors Lay them out head-to-tail
B B Parallelogram law of Addition A + B A Head to tail: Connect first head and last tail (problem: no common reference, so need to wait!) Tail to tail: Connect diagonal of parallelogram (problem: still only do 2 at a time) Best: Decompose vectors and add components (Later)
A - B Subtracting - B A
A = a A |a | = 1 a = A/|A| Unit/Base Vector Vector = Direction x Magnitude (Unit Vector) (Component)
Ay A = x Ax + y Ay y Ax x Unit/Base Vector y A Resolving/decomposing a vector A (Ax, Ay) Ax = Acosq, Ay = Asinq Building/composing a vector (Ax,Ay) A A = (Ax2 + Ay2) q = tan-1(Ay/Ax) q x
B = x Bx + y By (A+B) = x(Ax+Bx) + y(Ay+By) A = x Ax + y Ay Why compose/decompose? y Ay A q y x Ax x Can treat components as scalars !! Handle all of them independently!!
B q A Multiplying ? Need to take into account angle q between A and B Scalar Product A.B Vector Product A x B A.B = ABcosq
Multiplying ? Need to take into account angle q between A and B Scalar Product A.B Vector Product A x B B q A A.B = ABcosq (Projection)
n B q A Multiplying ? Need to take into account angle q between A and B Scalar Product A.B Vector Product A x B B q A A x B = ABsinq n (Area) Gives normal to a plane of vectors A.B = ABcosq (Projection) Gives angle between vectors
n B q A Multiplying ? Need to take into account angle q between A and B Vector Product A x B A x B = ABsinq n (Area) PRACTISE THIS -- MAKE YOUR OWN MODELS !!
n B q A Interchanging A and B Scalar (Dot) Product A.B Vector (Cross) Product A x B B q A A x B = - B x A A.B = B.A Orthogonal vectors have zero scalar product Parallel vectors have zero vector product
= 0 = 0 = 0 = 0 = 0 = 0 = x = z = y = 1 = 1 = 1 x x x x z x z x y x y x x . x . z . z . y . y . x x x x z z z z z y y y y y x - z y x z y Coordinate Systems Helps decompose vectors and deal with scalar components x +
B = x Bx + y By + z Bz A. B =Ax.Bx + Ay.By + Az.Bz A = x Ax + y Ay + z Az z y A x B = det Can see why A x B = -B x A ! x y z Ax Ay Az Bx By Bz x Using unit vectors for products
Combining more vectors Scalar Triple Product A.(B x C) Vector Triple Product A x (B x C) Other combos won’t do ! A.(B.C), Ax(B.C) not defined
A A C C q q B B Combining more vectors Scalar Triple Product A.(B x C) Vector Triple Product A x (B x C) Volume A.(B x C) = B.(C x A) = C.(A x B) = -A.(C x B) etc. A x (B x C) not simply related to (A x B) x C
C B q A Bac-Cab Rule Vector Triple Product A x (B x C) A x (B x C) = B(A.C) – C(A.B) Bac-Cab Rule
z y A. (B x C) = x Using unit vectors for products Ax Ay Az Bx By Bz Cx Cy Cz det