rotational_mechanics.gif (17954 bytes)

CENTRIPETAL FORCE: EARTH-MOON MODEL
(TWO BODY SYSTEM)








EQUIPMENT
    redball.gif (326 bytes) Hand-Crank Rotator
    redball.gif (326 bytes) Large Two Body System Model (m1 = 6m2)
  



NARRATIVE
            A large and small two body system model of the same proportions (1 to 6) are available. The large one is easier to see.

            The two bodies are free to slide along a rod which rotates perpendicular to the axis of rotation. The two bodies are tied together with a length of string. Since

m2 = 1/6m1  

m2 must be placed 6 times the distance from the axis of  rotation as m1 for the two bodies to remain balanced when rotating.