
Vector
⚫Introduction⚪ Those quantities which have both magnitudes and direction are called Vector .
Example : velocity ,accerelation , weight , force are some vector quantities.
⚫ Representation of vectors :
⚪ Geometrically a vector is represented by a line segment. For example ,
. Here A is called the initial point and B is terminal point.
Magnitude or modulus of a is expressed as
⚫ Types of Vector
⚪ Zero vector or null vector : A vector whose magnitude is zero is called zero or null vector.
⚪ Unit Vector : A vector whose magnitude is unity (1). The unit vector in the direction of a vector a is denoted by
⚪ Collinear or Parallel Vector : Vectors having the same or parallel supports are called collinear or parallel vectors
⚪ Co-initial Vector : Vectors having the same initial point.
⚪ Coplanar Vector : A system of vectors is said to be coplanar, if their support are parallel to the same plane.
⚪ Coterminous Vectors : Vectors having the same terminal point.
⚪ Equality of Vectors : Two vectors a and b are said to be equal if
i) |a|= |b|
ii) They have the same or parallel support
⚫ Addition Of Vectors
⚪ Triangle Law of addition :
If in Δ ABC
AB = a , BC = b , AC = c , then AB + BC = AC i.e., a + b = c
⚪ Parallelogram law of addition :
If in a parallelogram OACB , OA = a , OB = b , OC = c , Then OA + OB = OC , it means a + b = c , where OC is the diagonal of the parallelogram OABC
⚪ Addition in component Form :
If the vectors are defined in terms of i , j and k. It means if
a = a1i + a2j + a3k
b = b1i + b2j + b3k
Their sum is defined as :
a + b = (a1 + b1 )i + (a2 + b2 )j + (a3 + b3 )k
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