Physics Experiment
Range of a Projectile - 2
Purpose:
The text makes some claims regarding the range of a projectile
launched at an angle, namely:
- the maximum range of the projectile occurs at a launch angle
of 45o with respect to the horizontal.
- a projectile launched at an angle
with respect to the horizontal will have the same range as a
projectile launched at an angle of 90o - .
This experiment will test these predictions.
Equipment:
Equipment used for this investigation might include:
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Pasco projectile launcher
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2.5 cm projectile
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metric tape measure
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carbon paper
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c-clamp
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goggles
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scrap paper
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stack of books and/or magazines
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data table (*doc
file)
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Safety Issues:
- You are incredibly unlikely to be injured by the plastic
projectile, however:
- wear goggles at all times
- keep your face away from the end of the barrel of the
projectile launcher.
Procedure:
Setup:
- The statements above are valid only if the projectile lands at
the same height at which it is launched. Therefore, you have to
construct a "landing zone" from a stack of books/magazines (or
something) so that the projectile is caught at the same height as
the "mouth" of the projectile launcher.
- Fasten the projectile launcher to the lab table with a c-clamp
to prevent it from moving during your measurements.
Taking the Data:
- Set the angle of the projectile launcher to the first angle in
the data table.
- Use the "ramrod" to push the projectile down into the barrel
of the launcher. The launcher will shoot the projectile at 3
different speeds. You will hear and feel a click as the projectile
reaches each position in the barrel. Indoors, low or medium
speed is best.
- The precise landing spot of the projectile can be difficult to
judge, so:
- first, place and adjust your stack of books so
that the projectile hits it.
- now that you know the approximate landing spot, place a
sheet of scrap paper on the top of your "landing zone", and
place a piece of carbon paper inky-side down on the paper, the
projectile will leave a mark where it lands.
Shoot
the projectile launcher at this angle 4-5 times. You should get a
pattern of dots on the paper similar to the one shown at right.
You could measure the distance to each of the hits and calculate
the average, but it will be accurate enough for our purposes if
you determine a visual average from the pattern and measure and
record its range. - Change the projectile launcher's angle, and go back to step
2.
Results
Construct a graph of range versus angle for the projectile
launcher. Be sure to label the graph carefully and neatly.
Conclusions:
Do you think that your results confirm the textbook's claims about
the range of a projectile? Why do you think so?
last update October 13, 2002 by JL
Stanbrough