3A40.20 SHM: Shadow projection of pendulum maps closely image of peg moving on circular disk

PURPOSE: To demonstrate the relation between circular (cyclic) motion and the simple harmonic motion of a pendulum.

DESCRIPTION: Carbon arc lamp (unfocused) is used to project a shadow on the wall of the lecture hall. When timed properly, the period of motion of the peg will exactly match the period of the pendula.

SETUP TIME: Quite awhile to get it all right. (Difficulty factor of 8.) But it will work every time if it is set up properly.

COMPONENT LIST:

    


  1.  Carbon Arc Lamp					Light Source Shelf


  2.  Peg on disk						Top of CM Shelves


  3.  Variable Speed Driver for Peg			Not available at this time


  4.  Pendula						Pendulum box, CM shelves


  5.  Stand for pendulum					Stand area, CM shelves

SUGGESTIONS:

REFERENCES: PIRA 3A40.20

OTHER NOTES: This demonstration is very impressive and will garner lots of oohs and aahs.