Title Vectors 4.0.pdf ✅

Vectors 1 3 Vectors 1. Physical Quantities In physics we deal with two type of physical quantity one is scalar and other is vector. Each scalar quantity has magnitude. Example : mass, speed, distance etc. Scalar quantities can be added, subtracted and multiplied by simple laws of algebra. 1.1 Vector If a physical quantity in addition to magnitude - • has a specified direction. • Obey commutative law of addition ABBA +=+  • Obeys the law of parallelogram of addition, and then only it is said to be a vector. If any of the above conditions is not satisfied the physical quantity can not be a vector. If a physical quantity is a vector it has a direction, but the converse may or may not be true, i.e. if a physical quantity has a direction, it may or may not a be vector. e.g. pressure, surface tension or current etc. have directions but are not vectors. The magnitude of a vector (A)  is the absolute value of a vector and is indicated by |A|  or A. Example Displacement, velocity, acceleration, force etc. 1.2 Representation of vector Geometrically, the length of a vector is proportional to its magnitude and arrow represents direction of the vector. Symbolically, vector is represented by A  Key Points • If a vector is displaced parallel to itself it does not change (see Figure) BB�⃗ Transition of a vector parallel to itself CC⃗ AA⃗ AA⃗ = BB�⃗ = CC⃗ • If a vector is rotated through an angle other than multiple of 2π (or 360°) it changes (see Figure). BB�⃗ AA⃗ θ AA⃗ ≠ BB�⃗ Rotation of a vector • Two vectors are called equal if their magnitudes and directions are same, and they represent values of same physical quantity. Tail Length (magnitude) Head