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B a l l i s t i c P e n d u l u m A c c e s s o r y
E x p e r i m e n t 1 : B a l l i s t i c P e n d u l u m
8
012-09842C
3.
Launch the ball so that it is caught in pendulum.
4.
After the pendulum has swung out and back, stop data collection.
5.
Note the maximum angular displacement measured by the RMS. Record it in
Table 1.1.
6.
Repeat steps 1 through 5 several times.
7.
Calculate the average maximum displacement,
max
.
Find the Mass and Center of Mass
1.
Fire the ball one more time (without recording data). Catch the pendulum near
the top of its swing so it does not swing back and hit the launcher (this will pre-
vent the ball from falling out or shifting).
2.
Remove the pendulum from the RMS.
3.
Remove the screw from the pendulum shaft.
4.
With the ball still in the catcher, place the pendulum at the edge of a table with
the pendulum shaft perpendicular to the edge and the counterweight hanging over
the edge. Push the pendulum out until it just barely balances on the edge of the
table. The balance point is the center of mass. (See Figure 1.2.)
5.
Measure the distance,
r
, from the center of rotation (where the pendulum was
attached to the RMS) to the center of mass.
r
= _____________________.
6.
Remove ball from the catcher.
7.
Measure the mass of the pendulum (without the ball).
m
pend
= _______________
8.
Measure the mass of the ball.
m
ball
= _____________________
Table 1.1: Maximum
Angular Displacement
Trial
Angle
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Trial 6
Avg:
max
=
r
Balance point
Figure 1.2: Pendulum-ball system balanced on table edge
