Simple Pendulum

Monday, 11 June 2018

11:24 AM

If a pendulum undergoes periodic motion for angles smaller than 10 degrees, it can be considered to move under simple harmonic motion

 

Such that

 

 Equating

 

 for


 

 

 

Also,

So therefore:

And so,

 

The period and frequency of a simple pendulum depend only on the length of the string and the acceleration due to gravity.

The mass of the bob is independent, and doesn't affect the  motion of the pendulum.

All simple pendula that are of equal length and are at the same location oscillate with the same frequency.

 

 

 

Machine generated alternative text:
• The tangential motion is then 
described by: 
—m g sin 0 
mas=m 
sin 
s=LO 
Small angle 
approximation 
When 0 is small, a simple 
pendulum's motion can be 
modeled as simple harmonic 
motion about the equilibrium 
position 0 
d20 
radian 
—mg 0 
SHM! 
tangential 
radial 
Frictionless pivot 
cord 
Bob 
mg sin 0 
Gravitational 
force 
mg cos 0 
mg

 

Machine generated alternative text:
SHM>Simple pendulum... 
• Compare 
What we just derived: 
General equation of motion 
for SHM in terms of the 
angular frequency: 
d20 
There is no dependence on the 
mass of the bob! 
Angular frequency of an 
oscillating pendulum 
Acceleration 
due to gravity 
Length 
of cord 
Period

 

Created with Microsoft OneNote 2016.