-Simple Pendulum-Physical Pendulum-Torsional

Pendulum

- AP Physics CMrs. Coyle

http//article.wn.com/view/2010/08/22/Crystal_Moun

tain_will_feature_new_gondola_terrain_park/

The Simple Pendulum

- The motion of a simple pendulum is very close to

a SHM oscillator, if the angle is lt10o

- The tangential component of mg is the restoring

force - sLsin q
- For small values of q, sin q q
- Since a is proportional to q this motion is SHM

and let ?2g/L

Period of the Simple Pendulum

- q qmax cos (wt f)
- Angular frequency
- Period

- Question If a pendulum was taken to a planet

where the acceleration due to gravity was four

times that of g on the earth, how would the

period change?

Physical Pendulum

- An object that oscillates about a fixed axis (not

through its center of mass) and the object cannot

be approximated as a particle. - Torque Ia
- For small angles sin??

Period of the Physical Pendulum

- Since a is proportional to ? the motion has the

form of an object in simple harmonic motion. - Angular frequency
- Period

Torsional Pendulum

- Restoring torque
- t -kq Ia
- k is the torsion constant of the wire

Period of Torsional Pendulum

- Angular frequency
- Period