PASCO ME-6964 PAStrack Wheel Set - Manual (Page 7)

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M o d e l N o . M E - 6 9 6 4 S u g g e s t e d A c t i v i t i e s
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5. Attach a motion sensor to the end of the PAStrack with wheels to record the
velocity of the cart relative to the PAStrack with wheels.
Procedure
Start data collection, then start the motorized cart and observe what happens.
Analysis
1. Before looking at the motion-sensor data, consider the motion of the cart in the
lab reference frame. Did the cart’s speed after the collision appear to be greater
than, less than, or equal to its speed before the collision?
2. Now consider the motion of the cart as measured by the motion sensor. In the
sensor’s reference frame, was the cart’s speed after the collision greater than, less
than, or equal to its speed before the collision?
Activity 5: Inclined Plane
When you release the PAStrack with wheels on an inclined plane, it undergoes con-
stant acceleration. When you hold the PAStrack with wheels still and release a
dynamics cart on top of it, the cart undergoes the same constant acceleration. What
happens when both the PAStrack with wheels and dynamics cart are released
together?
1. Stack a dynamics cart
on the PAStrack with
wheels on an inclined
stationary track (as pic-
tured), but don’t release
them yet.
2. Predict how the cart will move relative to the PAStrack with wheels and relative
to the stationary track.
3. Release them. Was your prediction correct?
4. For comparison, stack the cart on the PAStrack with wheels on a level stationary
track. Predict what will happen when you pull the PAStrack with wheels so that it
accelerates. Try it. How does the cart move relative to the stationary track? How
does it move relative to the PAStrack with wheels?
5. Why does the system behave differently when the acceleration of the PAStrack
with wheels is caused by your hand compared to when the acceleration is caused
by gravity?
Activity 6: Rotational Inertia
1. Stack a solid disk and
a ring on the PAStrack
with wheels on a level
stationary track. Pre-
dict what will happen
when you pull the
PAStrack with wheels
so that it accelerates.
Try it. How do the disk and ring move relative to each other? How do they move