Projectile Motion & Energy
Name: __________________________
PROJECTILE MOTION PHeT: Pre-Lab Investigation
Block: ____
Date: _______________
PRE-LAB: What Do You Think?
One day after school you are enjoying a can of soda. After it’s empty you decide to toss it in the trashcan. What
variables determine whether or not you make the shot?
INVESTIGATE: Key terms and measurements in Projectile motion that you need to keep track off & record/measure.
Write out a definition for each term below; think of you throwing the can. Draw an arrow in Figure-2 for the three
measurements of Projectile motion.

Range/Distance –

Height –

Time –
ACTIVITY: Open the link http://phet.colorado.edu/sims/projectile-motion/projectile-motion_en.html
FIGURE-1
FIGURE-2
GOAL: Perfect aim: Test 3 variables by changing the numbers or objects:
1. Play with the simulation for 5 to 10 minutes; observe and then start the
activity. Find the combination of variables that hits the center of the
target.
2. Then, decide the 3 variables you will focus on (see FIGURE-1). Write
them down and draw a hypothesis about how this variable will affect or
not the distance travelled (aim). Select diameter, mass, initial speed in
the direction it is fired, angle, object or air resistance.
3. Change the variable one by one and record what happened. Complete
the table below by listing what happened as you changed the variable
by increasing or decreasing it; show results in values/ numbers.
4. Draw a conclusion in words and decide if the horizontal distance travelled is independent or dependent
on the variable you changed.
HYPOTHESIS: Predictions (steps 1 and 2)
Variable
Predicted Effect of Variable On Motion of Projectile and its Target
From FIGURE-1
FIGURE-2
1)
If I increase it,
If I decrease it,
2)
If I increase it,
If I decrease it,
3)
If I increase it,
If I decrease it,
SIMULATION: Step-3 Lab Activity – Online. Open up the University of Colorado, PhET Projectile Motion simulation
(http://phet.colorado.edu/new/index.php). Spend a few minutes familiarizing yourself with the controls of the
simulation before you begin the lab below.
Use the simulation to test your predictions. Fill in the table below with the variables and their effect on the motion of the
projectile as determined by their parameters.
Variable
Manipulation
On Target
Increase
Decrease
On Target
Increase
Decrease
On Target
Increase
Decrease
Actual Effect of Variable On Motion of Projectile
Range/distance(m)
Height (m)
time (s)
Conclusion: Step 4
Variable
Effect of Variable On Motion of Projectile and its Target
Dependent or independent of the “variable”. It increase as the other increase?
1)
The horizontal distance is ….
The Height is ….
The time to hit the ground is …..
2)
The horizontal distance is ….
The Height is ….
The time to hit the ground is …..
3)
The horizontal distance is ….
The Height is ….
The time to hit the ground is …..
Conclusion Questions:
Compare your predicted effects with your actual effects and answer the following questions.
1. List and explain the predictions that you found to be incorrect after performing the test.
2. Name at least two things that surprised you about projectile motion after performing the test.
3. The launch angle is a key variable. If you didn’t test it; then go back and change it and make the
following observations.
a. What angle causes the largest height?
b. What angle causes the largest range?
4. Does the mass of the object matter as long as you can launch each object with the same initial speed?