Vectors By Aruna
A VECTOR? Describes the motion of an object A Vector comprises Direction Magnitude We will consider Column Vectors General Vectors Vector Geometry Size
Column Vectors Vector a COLUMN Vector 4 RIGHT 2 up a NOTE! Label is in  BOLD . When handwritten,  draw a wavy line  under the label i.e.
Column Vectors Vector b COLUMN Vector? 3 LEFT 2 up b
Column Vectors Vector u COLUMN Vector? 4 LEFT 2 down n
Describe these vectors b a c d
Alternative labelling A B C D F E G H
General Vectors A Vector has BOTH a Length & a Direction k can be in any position All 4 Vectors here are EQUAL in Length and Travel in SAME Direction. All called k k k k k
General Vectors A B C D -k 2k F E Line CD is Parallel to AB CD is TWICE length of AB Line EF is Parallel to AB EF is equal in length to AB EF is opposite direction to AB k
Write these Vectors in terms of k A B C D E F G H 2k 1½k ½k -2k k
Combining Column Vectors k A B C D
Simple combinations A B C
Vector Geometry Consider this parallelogram Opposite sides are Parallel OQ is known as  the resultant  of  a  and  b Q O P R a b
Resultant of Two Vectors Is the same, no matter which route is followed Use this to find vectors in geometrical figures
Example = a + ½b Q O P R a b . S S is the Midpoint of PQ. Work out the vector
Alternatively = a + ½b = b + a - ½b = ½b + a Q O P R a b . S S is the Midpoint of PQ. Work out the vector
Example M is the Midpoint of BC = -q + p = p - q A B C p q M Find BC AC= p, AB = q BC BA AC = +
Example M is the Midpoint of BC = ½(p – q) A B C p q M Find BM AC= p, AB = q BM ½BC =
Example M is the Midpoint of BC = q + ½(p – q) = q +½p - ½q = ½q +½p  = ½(q + p)  = ½(p + q)  A B C p q M Find AM AC= p, AB = q AM + ½BC = AB
Alternatively M is the Midpoint of BC = p + ½(q – p) = p +½q - ½p = ½p +½q  = ½(p + q)  A B C p q M Find AM AC= p, AB = q AM + ½CB = AC

Vectors

  • 1.
  • 2.
    A VECTOR? Describesthe motion of an object A Vector comprises Direction Magnitude We will consider Column Vectors General Vectors Vector Geometry Size
  • 3.
    Column Vectors Vectora COLUMN Vector 4 RIGHT 2 up a NOTE! Label is in BOLD . When handwritten, draw a wavy line under the label i.e.
  • 4.
    Column Vectors Vectorb COLUMN Vector? 3 LEFT 2 up b
  • 5.
    Column Vectors Vectoru COLUMN Vector? 4 LEFT 2 down n
  • 6.
  • 7.
  • 8.
    General Vectors AVector has BOTH a Length & a Direction k can be in any position All 4 Vectors here are EQUAL in Length and Travel in SAME Direction. All called k k k k k
  • 9.
    General Vectors AB C D -k 2k F E Line CD is Parallel to AB CD is TWICE length of AB Line EF is Parallel to AB EF is equal in length to AB EF is opposite direction to AB k
  • 10.
    Write these Vectorsin terms of k A B C D E F G H 2k 1½k ½k -2k k
  • 11.
  • 12.
  • 13.
    Vector Geometry Considerthis parallelogram Opposite sides are Parallel OQ is known as the resultant of a and b Q O P R a b
  • 14.
    Resultant of TwoVectors Is the same, no matter which route is followed Use this to find vectors in geometrical figures
  • 15.
    Example = a+ ½b Q O P R a b . S S is the Midpoint of PQ. Work out the vector
  • 16.
    Alternatively = a+ ½b = b + a - ½b = ½b + a Q O P R a b . S S is the Midpoint of PQ. Work out the vector
  • 17.
    Example M isthe Midpoint of BC = -q + p = p - q A B C p q M Find BC AC= p, AB = q BC BA AC = +
  • 18.
    Example M isthe Midpoint of BC = ½(p – q) A B C p q M Find BM AC= p, AB = q BM ½BC =
  • 19.
    Example M isthe Midpoint of BC = q + ½(p – q) = q +½p - ½q = ½q +½p = ½(q + p) = ½(p + q) A B C p q M Find AM AC= p, AB = q AM + ½BC = AB
  • 20.
    Alternatively M isthe Midpoint of BC = p + ½(q – p) = p +½q - ½p = ½p +½q = ½(p + q) A B C p q M Find AM AC= p, AB = q AM + ½CB = AC