Handbook of High Speed Photography - IET Labs, Inc.

Multiple-flash photographs taken in the classroom help teach the concept of acceleration.
With a Polaroid camera and Type 46L film, a positive transparency is available for projec
tion (life size) a few minutes after the students see the original action. The photos show a
classroom setup with ball about to be dropped and the resulting photographic record of the
travel of the ball. The ball is photographed at fixed time intervals. The widening gaps be
tween the images proves the rule of constant acceleration caused by the force of gravity
even to the most skeptical student.
A similar arrangement can be used to analyze the motion of a projectile (see opposite page).
In this experiment, a steel ball is launched by dropping it into a steel tube. The resulting
trajectory is photographed by multiple-flash techniques. If a scale is included in the setup,
then the horizontal and vertical components of velocity can be determined directly from the
photograph.
79