4
Photogate Timer
012-06379B
®
The following accessories are available to help extend the
utility of your model ME-9215B Photogate Timer. All
the accessories work equally well with either model. See
the current PASCO catalog for more information.
ME-9204B Accessory Photogate
The stereo phone plug of the ME-9204B Accessory
Photogate plugs into the phone jack on the rear of the
Photogate Timer, giving you two identical photogates
operating from a single timer. With the timer in Gate
mode, you can measure the velocity of an object as it
passes through one photogate, then again as it passes
through the second photogate. With the timer in Pulse
mode, you can measure the time it takes for an object to
pass between the two photogates. (Many of the experi-
ments in this manual are most easily performed using a
Photogate Timer with an Accessory Photogate.)
ME-9207B Free Fall Adapter
For easy and accurate measurements of the acceleration
of gravity, the ME-9207B Free Fall Adapter is hard to
beat. The Free Fall Adapter plugs directly into the phone
plug on the rear of the Photogate Timer. It comes with
everything you need, including two steel balls (of differ-
ent size and mass), a release mechanism, and a receptor
pad. The release mechanism and the receptor pad auto-
matically trigger the timer, so you get remarkably accu-
rate measurements of the free fall time of the steel ball.
ME-9259A Laser Switch
This highly collimated photodetector is identical to a
photogate, except that you use a laser (not included) as
the light source. You can now time the motion of objects
that are far too big to fit through a standard photogate.
Measure the period of a bowling ball pendulum or the
velocity of a car. The Laser Switch operates in all three
timing modes (Gate, Pulse, and Pendulum).
Accessories for the Photogate Timer
The following 10 experiments are written in worksheet form. Feel free
to photocopy them for use in your lab.
NOTE:
In each experiment, the first paragraph is a list of equipment
needed. Be sure to read this paragraph first, as the equipment needs
vary from experiment to experiment.
This manual emphasizes the use of an air track, but the air track experi-
ments can also be performed with dynamics carts. Many also require a
ME-9204B Accessory Photogate in addition to a Photogate Timer.
Collision experiments, such as experiments 6 and 7, require four times
to be measured in rapid succession and are therefore most easily per-
formed using two Photogate Timers.
10 Copy-Ready Experiments
