LAB – Projectile Motion – (Motion in TWO dimensions)
Name: ______________________
(22 points + 2 EC = 24/22 = 109%)
ASSIGNMENT: Working in groups of 2-3 students, you will need to calculate the horizontal distance a
projectile will travel based upon the elevation of the launcher, the velocity of the projectile, and the
angle that the projectile is launched from – for three different angles.
This will be a “group grade” and only one lab write up will be required for each group. HOWEVER, each group member should
be working through the mathematics to ensure that the math was done correctly AND so that each group member understands
“how” to do all of the math as all students will see these kinds of math problems on a future test.
A) You will determine this horizontal distance of the projectile BOTH theoretically
(mathematically) and experimentally (actually using the launcher) – for three different angles.
9 points = 2 points for each mathematical and 1 point for each experimental
B) You will then determine the percent error between the distance values (theoretical &
experimental) – for three different angles. 3 points
C) You will also need to create an excel document (worksheet) which will allow you to quickly
calculate the distance of the projectile by entering in values of elevation, velocity, and angle.
NOTE: your excel document should provide calculations that match your theoretical values and
your experimental values will usually have some degree of experimental error (percent error).
6 points = 4 points if is produces the correct values and 2 points for showing all of the proper labels and units
D) Describe three sources of experimental error that cause you experimental values to be
different from your theoretical values. For each of these three sources of experimental error,
you need to explain how it would cause your experimental measurements to be higher or lower
than they should be. (Lower because…) 6 points = 2 points each
***Remember to use the correct units, labels and significant figures for all problems. Your teacher or a
fellow classmate should be able to follow all of your work. Include a written description if it is
difficult to show all of your work mathematically.
1) Set up your projectile launcher and Vernier Lab Quest with two photogates. You will need to
measure the distance between the two photogates sensors.
2) On the Vernier Lab Quest, change the MODE to “photogate” and “Pulse”. You must also enter
the distance between the two photogates (see #1 above). The two photogates will be used to
measure the velocity of the projectile. It will measure the time between the two photgates and
use the distance between the photogates that you entered (Velocity = distance / time).
3) Since the two photogates are the location where you will measuring your velocity, this is the
point that should be used to determine your elevation and your horizontal distance.
4) You will need to use the projectile launcher for three different angles.
5) The first angle will be 55.0°. Then chose two different angles that are at least 10.0 degrees
different from 55.0°.
6) It is recommended that you conduct more than one trial for each of the three different angles.
Please note that the velocity of each trial may be different. These differences will be due to how
you hold the two photgates relative to the projectile. Your teacher will explain the importance
of how to hold the photogates during this laboratory investigation.
7) Remember to use the correct units and make your measurements as precisely/accurately as you
can (remember your significant figures.)