  Its dimensional formula is also [M0L1T0].            Uniform Velocity
  The magnitude of displacement is less
                                                        If an object undergoes equal displacements in
   than or equal to the magnitude of distance.
                                                        equal intervals of time, then it is said to be
  |Displacement| ≤ |Distance|
                                                        moving with a uniform velocity.
                                                        Non-Uniform Velocity
                                                        If an object undergoes unequal displacements
                                                        in equal intervals of time, then it is said to be
                                                        moving with a non-uniform or variable
Speed (v)                                               Relative velocity
  It is the rate of change of distance with               Relative velocity of an object with respect
   respect to time.                                         to another object is the time rate of change
  It is a scalar quantity and its unit is                  of relative position of one object with
   meter/second (m/s).                                      respect to another object.
  Dimension of speed is [M0L1T-1].                        Relative velocity of object A with respect
  Average                    speed            is           to object B
         s Total distance travelled                        V AB  V A  VB
    va     
         t      Total time taken
  Speed of Light = 3 x 108 m/s                         Acceleration (a)
  Speed of Sound = 343 m/s
                                                           The time rate of change of velocity is
  The first scientist to measure speed as                  called acceleration.
   distance over time was Galileo.
                                                           Its unit is m/s2
Velocity ( v )
                                                           Its dimensional formula is [M0LT-2]
  It is the rate of change of displacement                It is a vector quantity.
   with respect to time.
                                                           Average acceleration over a period of time
  It is a vector quantity and its unit is                  is the change in velocity v) divided by
   meter/second (m/s).                                      the duration of the period t)
  Dimension of speed is [M0L1T-1]
                                                                 v v 2  v1
  Average                  velocity           is            a      
                                                                 t      t
         s    Displacement
    va                                                   Acceleration of an object is zero, if it is at
         t Total time taken
                                                            rest or moving with uniform velocity.