PASCO ME-6950 PAScar with Mass - Manual (Page 5)

012-07361B PAScar with Mass
4
Procedure
1. Once you have roughly determined the range of the cart, clearly mark a distance d that is
about half way out from the start. Measure this distance and record it at the top of Table
1.1.
2. Using a stopwatch with a lap timer and metric tape, it is possible to determine t
1
, T and D
for each launch. Practice this step a few times before you start recording data.
NOTE: To eliminate reaction time errors, it is very important to have the person who
launches the cart also be the timer!
3. Launch the car and record the data described in the previous step for six trials. To cock
the spring plunger, push the plunger in, and then push the plunger slightly upward to
allow one of the notches on the plunger bar to “catch” on the edge of the small metal bar
at the top of the hole. (Don’t count the trials in which the timer feels that a distraction
interfered with the measurement.) Record your best trials in Table 1.1.
4. Using the equations described in the theory section and the data recorded in the table, do
the calculations needed to complete the table.
Data Analysis
t
1
(sec) T (sec) D (cm) v
o
(cm/s) a (cm /s 2 ) t
1
(sec)
% Diff.
Theory Experiment
Trial
1
5
4
3
2
6
Table 1.1
Questions
1. Is there a systematic difference between the experimental and calculated values of t
1
? If
so, suggest possible factors that would account for this difference.
2. Can you think of a simple follow-up experiment that would allow you to determine how
much the cart’s “deceleration” was affected by floor slope?
d = _______cm