PASCO ME-6831 Ballistic Pendulum_Projectile Launcher - Manual (Page 45)

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M o d e l N o . M E - 6 8 3 0 E x p . 9 : P r o j e c t i l e V e l o c i t y — E x a c t M e t h o d
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Questions
1. Is there another way to measure the muzzle velocity that you could use to check your results? You may want
to use that second method and compare the two answers.
2. What sources of error are there in this experiment? How much do these errors affect your result?
3. It would simplify the calculations if kinetic energy were conserved in the collision between the ball and the
pendulum (see “Ballistic Pendulum Theory” in the Introduction). What percentage of the kinetic energy is lost
in the collision between the ball and pendulum? Would it be valid to assume that energy was conserved in that
collision?
4. Does increasing the mass of the pendulum increase or decrease the efficiency of the energy transfer in the col-
lision? Try it.
5. The “Projectile Velocity—Approximate Method” experiment uses the approximate equation for velocity:
• What is the value of velocity when you use this equation? Is there a significant difference between these two
calculated values? What factors would increase the difference between these two results? How would you
build a ballistic pendulum so that the approximate equation gave better results?
v
b
M
m
----- 2gR
cm
1

cos –
 
=