Velocity of the particle at the time 't' is :
Note (1): If v > 0 then s is increasing and the particle is moving from left to right.
Note (2): If v < 0 then s is decreasing and the particle is moving from right to left.
Note (3): If v = 0 then the particle comes to rest.
Acceleration :
The rate of change of velocity i.e.
is called the acceleration of the particle at the instant. It is denoted by 'a'.
Acceleration of the particle at the time 't' is: 
= 
Angular velocity :
Let 'O' be a fixed point in a plane and 
be a fixed ray. Let P be the position of a particle on a curve C at the time 't' such that 
If 
t is any change in t and θ is the corresponding change in θ then the rate of change in θ is 
which is called the angular velocity of the particle about O. It is denoted by 
Angular Acceleration :
The rate of change of angular velocity is
which is called the angular acceleration of the particle.
