Physics with Computers
14 - 1
A swinging pendulum keeps a very regular beat. It is so regular, in fact, that for many years the
pendulum was the heart of clocks used in astronomical measurements at the Greenwich
There are at least three things you could change about a pendulum that might affect the
(the time for one complete cycle):
the amplitude of the pendulum swing
the length of the pendulum, measured from the center of the pendulum bob to the point of
the mass of the pendulum bob
To investigate the pendulum, you need to do a
experiment; that is, you need to make
measurements, changing only one variable at a time. Conducting controlled experiments is a
basic principle of scientific investigation.
In this experiment, you will use a Photogate capable of microsecond precision to measure the
period of one complete swing of a pendulum. By conducting a series of controlled experiments
with the pendulum, you can determine how each of these quantities affects the period.
Measure the period of a pendulum as a function of amplitude.
Measure the period of a pendulum as a function of length.
Measure the period of a pendulum as a function of bob mass.
Power Macintosh or Windows PC
Universal Lab Interface
2 ring stands and pendulum clamp
masses of 100 g, 200 g, 300 g
Graphical Analysis or graph paper