PURPOSE: To determine the speed of an air gun pellet using rotational kinematics.

DESCRIPTION: A pellet is shot from the air gun with a linear velocity v, such that it passes between the two rotating discs which have a separation d and are rotating with an angular velocity w. The angle a that the two discs rotate while the pellet is traveling between them is determined by inspecting the two discs. The velocity of the pellet is then determined by using the relation: v = w d / a. In this case the angular velocity w of the rotating discs is 1800 rpm, and the distance d between the discs is 1 meter.

SUGGESTIONS: CAUTION: Lift apparatus by handles only. DANGER: Gun can be very dangerous. Pump eight times before firing to assure uniform velocity for several trials.

REFERENCES: (PIRA unavailable.) See also Demonstrations C7-51: BALLISTIC PENDULUM - PELLET GUN and C7-53: AIR TRACK - SPEED OF AIR GUN PELLET for other ways to determine the pellet velocity.

EQUIPMENT: Pellet gun with pellets, disc rotating mechanism with paper discs, and backstop.

SETUP TIME: 5 min.

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