Notes and Important Points on Circular Motion for JEE Main 2015 by ednexa.com

1. Introduction to the subject
Motion

2. Circular Motion
By- Prof. Dnyanesh
Vaidya

3.  What does motion mean ?

4.  Displacement of particle with
respect to other particle is known as
motion.

5. Types of Motion
Motion
Translational/
Linear
Circular/
Rotational
Oscillatory
/Vibration

6. Circular motion
 Motion of a particle along the
circumference of a circle is called
circular motion.

11. Position Vector or Radius Vector
 A vector drawn from the centre of the
circular path to the position of the
particle performing circular motion at a
instant, is called the position vector or
radius vector

12. Angular Displacement
 Angular displacement θ of a particle in
a given time is defined as the angle
traced by its radius vector in that time
at the origin of frame of reference.
 ∴ angular displacement = ∠BOA = θ
 
arcBA
But
r
  
s
r
It is expressed in radian
 
uur s
r

14. Angular Velocity
 The rate at which the angular displacement
takes place is called angular velocity (ω)

 

uur
ur
qvAverage angular velocity
t
The instantaneous angular velocity can be
obtained at limiting value of δt
 
 
   

uur
ur
t 0
d
lim
t dt
It is measured in rad/sec.

15. U.C.M.
 “ Motion of a body along the
circumference of a circle with
uniform linear speed or uniform
angular velocity.”

16. Angular Acceleration
 The rate of change of angular velocity
is called ‘angular acceleration (α)’
  
  2 1
av
t
 

  

i 2t 0
dw rad
lim It is measured in
t dt s

17. Thank You.