Physical Pendulum

Hanging objects may be made to oscillate in a manner similar to a simple pendulum. The motion can be described by "Newton's 2nd law for rotation":

where the torque is

and the relevant moment of inertia is that about the point of suspension. The resulting equation of motion is:

for small angles where
Show

This is identical in form to the equation for the simple pendulum and yields a period:

CalculationCompare to simple pendulum

Rod pendulumCircular geometriesCombinations
Index

Periodic motion concepts
 
HyperPhysics***** Mechanics R Nave
Go Back





Physical Pendulum Calculation

The period is not dependent upon the mass, since in standard geometries the moment of inertia is proportional to the mass.

For small displacements, the period of the physical pendulum is given by

For Isupport = kg m2
m = kg
g = m/s2
Lcm = cm
the period is T = s
Rod pendulumCircular geometriesCombinations
Index

Periodic motion concepts
 
HyperPhysics***** Mechanics R Nave
Go Back