Vernier Motion Encoder System - Manual (Page 4)

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The Additional Mass (MASS)
The 500 g mass is used to double the mass of the cart.
1. Insert the hex head of the #10-32 x 1-3/4″ screw into either of the side slots on the
cart from the flared end.
2. Fit the mass over the screw and position the mass and screw as required on the
cart.
3. Screw the small barrel onto the projecting end of the #10-32 x 1-3/4″ screw and
tighten to secure the mass.
Magnetic Bumpers
The Vernier dynamics carts are supplied with
magnets and hook-and-pile tabs. You may choose to
install either or both on your carts. 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.
To install magnets so that carts will repel one another, as well as 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 stop, in the same position as
an approaching cart, and verify that the south-pointing end of the compass is
attracted to the cart.
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Carts come with magnets, foam plugs, teardrop inserts, and a hex key to remove and
replace the screw holding the teardrop to the cart end. A magnetic compass is not
included.
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 top of the
teardrop-shaped plugs. 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 plug. This way any cart with hook-and-pile tabs will stick to any other.
Hook-and-pile equipped carts will stick together, creating a totally inelastic collision.
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.
Both the plunger and encoder carts have a mass of 500 g. Adding accessories will
change the mass.
Use of Additional Accessories and Sensors with the Encoder
System
The following examples show various sensors attached to a Vernier dynamics cart.
Sensors are not included with the Vernier Motion Encoder System.
Attach the Dual-Range Force Sensor (DFS)
1. Insert the hex head of the screw on the bottom of the post into the center slot of
the cart at the flare. The flats of the hex head should be parallel to the slot and the
washer should be above the slot to avoid marring the cart with the metal post.
2. Slide the post to the desired position on the cart and lightly tighten in place with
the knurled end of the post.
3. Place the DFS on the cart with the post through its central hole. Reposition the
post if necessary, and tighten. Tighten the plastic screw on the end of the sensor to
secure the DFS in place.
Plastic screw
Post