PASCO ME-9892 Ballistic Pendulum Accessory - Manual (Page 9)

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M o d e l N o . M E - 9 8 9 2 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
9
Analysis
1. Use your value of 
max
, the distance r, and Equation 1.5 to calculate the maxi-
mum height (h) that the center of mass rises as the pendulum swings up (see Fig-
ure 1.3).
(eq. 1.5) h = r (1 - cos ( 
max
))
h = _____________________
2. Use your value of h and Equation 1.4 to calculate the launch velocity of the ball.
V0 = _____________________
Question
The theory for this experiment ignores the rotational inertia of the pendulum. Because
the pendulum is not really a simple pendulum (a point mass on a massless rod), a sys-
tematic error is introduced. Does this simplistic analysis tend to give a launch velocity
that is too high or too low? (See Experiment 3 for a more exact treatment.)
Further Study
Use two photogates to measure the launch velocity of the ball. Compare this value to
the value you found using the ballistic pendulum.
x
h
r
q
max
x = r cos ( 
max
)
r = x + h
Figure 1.3:
Calculating
h