Plunger Cart
Experiments
8
012-14781A
Procedure
1. Place the Plunger Cart in its starting position and then launch it. To cock the spring plunger, push
the plunger in, and then push the plunger slight upward to allow one of the notches on the plunger
bar to “catch” on the bar inside the cart. Using a stopwatch and metric tape, determine the range d
and the total time spent rolling t. Record these in Table 2.1.
2. Repeat step 1 six times for each direction and enter your results in Table 2.1.
3. Using Eqn. 3, compute the accelerations corresponding to your data and an average acceleration
for each of the two directions.
4. Using the results of step 3, determine
µ
r
and
by algebraically solving for the two unknowns.
Table 2.1
Average Acceleration = ___________ cm/s
2
Average Acceleration = ___________ cm/s
2
Data Analysis
Coefficient of rolling friction = ________________ Floor Angle = ________________
Questions
1. Can you think of another way to determine the acceleration of the Plunger Cart? If you have time, try it!
2. How large is the effect of floor slope compared to that of rolling friction?
First Direction
Second Direction
Trial
d (cm)
t (s)
a (cm/s
2
)
Trial
d (cm)
t (s)
a (cm/s
2
)
1
1
2
2
3
3
4
4
5
5
6
6