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Insert the oblong nut into the bottom slot of the track and tighten. To attach the
pulley without a Photogate, use the short bolt to attach the pulley. Adjust the height
of the pulley as needed to keep the string level. To include a Photogate, slide the
plastic photogate mount over the vertical portion of the Pulley Bracket, with the
open slot outward and upward. Insert the Vernier Photogate into the mount, and pass
the long bolt through the bracket, and Photogate, capturing the threads of the bolt
with the Pulley.
Collision Tabs
The Vernier dynamics carts are supplied with
magnets and hook-and-pile tabs. These parts
are attached using removable Collision Tabs.
Since the magnets may interfere with certain
experiments using force sensors on the carts,
only install the magnets if you need them.
The magnets are useful in studying collisions with the magnets positioned so that
they are the same polarity on both sides and on both carts. This way the carts will
repel one another, and you can arrange a collision in which the carts never actually
touch. The collision will be very nearly elastic, unlike a collision using a spring or
any kind of contact.
The removable Collision Tabs have two sides. One is marked N, and the other is
plain. The plain side is for use with hook-and-pile material on tabs without magnets.
The Collision Tabs can be inserted either way, exposing or concealing any hook-
and-pile material. To quickly perform an experiment without magnets, remove the
Collision Tabs.
The Adjustable End Stop will hold magnets as well. Note that only low-speed
collisions with the End Stop will keep the cart on the track.
To install magnets on the Adjustable End Stop, use the following procedure:
1. Remove the teardrop from the cart end or the End Stop.
2. Insert the silver magnet (supplied with the cart) into the teardrop, oriented so that
the outside of the teardrop will attract the south-pointing end of a compass needle.
3. Insert a foam plug (supplied with the cart) into the teardrop.
4. Reinsert the tear drop into the cart end or the End Stop, and fasten the screw.
If you like, test by holding the compass near the cart or End Stop, in the same
position as an approaching cart, and verify that the south-pointing end of the
compass is attracted to the cart.
The magnets can be removed at any time by reversing this process. Store the
magnets away from computers.
To study totally inelastic collisions, place hook-and-pile tabs on the Collision Tabs
without magnets. Looking at the end of the cart, place a hook pad on the
left-hand plug, and a pile tab on the right-hand side. Center the pad on the round part
of the Collision Tab. This way any cart with hook-and-pile tabs will stick to any
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other. Hook-and-pile equipped carts will stick together, creating a totally inelastic
collision.
Plunger Cart
One cart includes a spring-loaded plunger for collisions. To use the plunger,
simultaneously press the horizontal button above the plunger and press the plunger
in until it locks. To release, press on the pin from the top of the cart. The plunger
force can be adjusted. To adjust the plunger release force, rotate the plunger while it
is extended. An uncalibrated scale is visible on the underside of the cart. Use this
scale to return to a previous setting.
The Plunger Cart is capable of superelastic collisions. To enable this mode, use a
small screwdriver to unlock the dark gray plastic plug below the main plunger.
Depress the plug using the screwdriver and rotate one-half turn counterclockwise to
unlock. The plunger will extend about 2 mm.
Lock the plunger as before to prepare for a superelastic collision. In a collision, the
plug will strike first and trigger the release of the plunger.
To disable superelastic collision mode, use a small screwdriver to depress and rotate
the plug one-half turn clockwise. It will lock in the flush position.
The plunger cart has a nominal mass of 250 g. Adding accessories such as sensors or
magnets will change the mass.
Use of Additional Accessories and Sensors
The following examples show various sensors attached to a Vernier dynamics cart.
Sensors are not included with the Dynamics Cart and Track System with Motion
Encoder.
Attach the Dual-Range Force Sensor (DFS)
1. Place the sensor over the two silver pins as
shown on the cart top sheet. Older force
sensors may require moving the pins to the
wide spacing option.
2. Use the large bolt to secure the sensor to the
cart as shown.
3. Configure the force sensor as needed with a
hook, bumper, or magnet.
Attach the Low-g Accelerometer (LGA)
The Accelerometer has mounting holes on the
cart top sheet.
1. To attach an accelerometer, place the sensor
over the mounting holes as shown on the
cart top sheet.
2. Use two small mounting bolts to secure the
sensor as shown.
