PASCO ME-6800 Projectile Launcher (Short Range) - Manual (Page 45)

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M o d e l N o . M E - 6 8 0 0 T e a c h e r ’ s G u i d e
0 1 2 - 0 5 0 4 3 G 41
2. Vertical distances were measured from the ground up for this graph. The intercept is the height of the launcher
above the ground when done this way.
3. The slope (measuring from the ground) is -0.118 for this example. Measuring down from the initial height
will give the same value, except positive.) In either case, the slope is:
4. The slope calculated here gives us an initial speed of 6.44 m/s. This compares favorably with the speed calcu-
lated in experiments 1 and 2.
Questions
1. Yes. This tells us that y is a function of x2.
2. A plot of y versus x would be parabolic instead of linear.
3. The projectile moves in a parabolic curve (if air resistance is neglected).
Exp. 5: Conservation of Energy
Analysis
1. Using the photogate method, the initial speed of the ball was found to be 4.93 m/s (for the short range
launcher at the medium range setting). The ball mass was 9.6 g, so the total kinetic energy was 0.117 J.
2. The ball reached an average height of 1.14 m (above the muzzle). The gravitational potential energy was
0.107 J.
3. The energy difference was 8.5% of the original kinetic energy.
Exp. 6: Conservation of Momentum in Two Dimensions
Setup
• If possible, use medium range setting instead of the short range setting. The medium range setting gives more
predictable results than the short-range setting.
Analysis
• Results for the x component of momentum should be within 5% of initial values. The total y component
should be very small compared to the x component.
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0
0.05
0.1
0.15
0.2
0.25
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Vertical Distance (m)
Horizontal Distance Squared (m^2)
f(x) = -1.181345E-1*x + 2.609457E-1
R^2 = 9.997926E-1
g
2v
0
2
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