Purpose:
The purpose of this activity is to the nature of a
projectile's motion and to explore a variety of questions
regarding projectiles.
Procedure and
Questions:
1. Navigate to the Projectile
Simulator page and experiment with the onscreen
buttons in order to gain familiarity with the control of
the animation. The launch speed, launch height and launch
angle can be varied by using the sliders or the buttons.
A trace of the object's motion can be turned on, turned
off and erased. The vector nature of velocity and
acceleration can be depicted on the screen. The animation
can be started, paused, continued, singlestepped or
rewound. And finally, the time of flight, the
horizontal displacement, and height are displayed during
the course of the animation.
After gaining familiarity with the program, use it to
answer the following questions.
Section 1: For
Horizontally Launched
Projectiles: Raise the launch height to
about 50 meters and adjust the launch angle to 0 degrees.
Conduct several trials to answer the following
questions.
2. Use the language of mathematics to describe the
path or trajectory of a projectile.
3. During the course of a trajectory, is the
horizontal component of the velocity a constant or a
changing value? ___________________ If it is a changing
value, then describe its changes (increasing, decreasing,
or ...).
4. During the course of a trajectory, is the vertical
component of the velocity a constant or a changing value?
___________________ If it is a changing value, then
describe its changes (increasing, decreasing, or
...).
5. Desribe the acceleration of a projectile 
direction, constant or changing magnitude, etc. Be
complete.
6. As a projectile falls vertically, it also travels
horizontally. Is the distance which it falls vertically
effected by its horizontal velocity? _______________ In
the space below, display some collected data which
clearly support your answer. Discuss how your data
provide support for your answer.
7. A classic mindbender: If a ball is dropped from
rest from an elevated position at the same instant that a
second ball is launched horizontally (from the same
height), then which ball will hit the ground first?
Assume the balls behave as projectiles.
Section 2: For Angle
Launched Projectiles: Return the launch
height to ground level. Conduct several trials to answer
the following questions.
8. Consider questions 25 in the previous section of
this lab (horizontally launched projectiles). Would
launching a projectile at an angle effect any of the
answers which you provided earlier? Consider path or
trajectory, horizontal velocity (v_{x}), vertical
velocity (v_{y}) and acceleration. Be thorough
and organized as you answer your questions.
9. At what point in the projectile's trajectory is the
velocity vector entirely horizontal (i.e., the vertical
component of velocity is zero)? __________ If
necessary, slow the simulation down using the Single Step
button
10. TRUE or FALSE:
The acceleration of projectile is 0 m/s/s at
the peak of the trajectory.
Identify the evidence which supports your
answer.
11. Pick a launch speed and angle and compare the time
required for the projectile to rise to the peak of its
trajectory to the time for the projectile to fall from
the peak of its trajectory. The Single Step button
and the Vector display can be used to assist in
your measurements. Repeat for other launch angles
if necessary. Describe your findings.
12. For a fixed launch velocity, what launch angle
(between 0 and 80 degrees) maximizes the time of flight
for an angle launched projectile? In the space below,
display some collected data which clearly support your
answer.
Set the launch speed to 30 m/s and the launch height
to 0 meters. Fill in the table below to investigate the
effect of launch angle on horizontal displacement.
Launch Angle
(deg)

Horiz.
Displacment (m)

10


20


30


40


45


50


60


70


80


13. Based on the data collected above, which launch
angle provides the maximum range (horizontal
displacement) for a projectile.
14. Describe any other obvious observations which you
could make from theinspection of the above data.
Summary Statement:
Discuss the motion of a projectile in terms of the
changes (or lack of changes) in its horizontal and
vertical motion parameters. Comment on such quantities
as horizontal velocity (v_{x}), vertical velocity
(v_{y}), horizontal acceleration (a_{x}),
and vertical acceleration (a_{y}). Do a bangup
job!