PURPOSE: To measure the angular velocity of a rotating object.
DESCRIPTION: An extender is placed on one of the arms of the Oberbeck Cross, which rotates freely on a precision bearing. The angular velocity is determined by measuring the time taken for the arm with the extender to progress one-half of one revolution, between the two photocell gates. Gate A starts the counter; gate B stops it.
REFERENCES: (PIRA 1Q20.20)
EQUIPMENT: Oberbeck cross with extender, photocell timer, and necessary clamps, as photographed.
SETUP TIME: 5 min.
Go back to Lecture-Demonstration Home Page.