Name: ____Cary and Charlie___
Date: ___9/20/11_
Period: __1__
PROJECTILE MOTION
Pre-Lab Investigation
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?
The wind (if its outside), the weight of the soda can, the distance between you and the trashcan.
Key Projectile Motion Measurements
Write out a definition for each term below.

Range – The area of variation between upper and lower limits on a particular scale

Height – Elevation above ground or a recognized level

Time –The indefinite continued progress of existence and events in the past, present, and
future regarded as a whole
Prediction Table
Complete the table below by listing what YOU THINK are the variables involved in projectile motion and
describe what YOU THINK their effect will be on the flight path.
Variable
Predicted Effect of Variable On Motion of Projectile
Wind
Will push the can off its path
Weight
Will prevent it from going certain distances
Distance
Might be too far to make it in the trashcan
Lab Activity – Online Simulation
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.
Test Your Predictions
Use the simulation to test your predictions. Fill in the table below with the variables and their effect on the
motion of the projectile.
Variable
Actual Effect of Variable On Motion of Projectile
Range
In the simulation, if the cannon is not in range of the target it cannot hit it
Height
In the simulation, if you don’t have the right height on the cannon it will miss
the target
Time
In the simulation, it shows that each object (whether it is a golf ball or car)
takes the same amount of time to reach the target
Launch angle
In the simulation, the angle you shot the cannon at had a big impact. The
cannon could be at the same place each time you shoot it off but the angle
couldn’t change or else you would have a different result each time.
Design a Test:
You’ve heard the claim that a bullet shot horizontally will strike the ground at the same time as a bullet dropped
from the same height. Use the PhET simulation to test this theory.
1. Describe IN DETAIL what you did to the variables on the simulation to test the theory:
I figured the golf ball and a bullet were the closest in size for the simulation and then I pointed the cannon
sideways. It was at the same height of the man’s towel so I shot the golf ball out and the towel hit the
ground just about .25 seconds faster. So the theory is false.
2. Record your findings (time of flight, distances, angles, etc):
Height- (-1.3 m)
Time- .5 seconds
Range- 9.4 m
3. Did you prove or disprove the claim?
Disprove
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.
Wind- the wind would push the can off track:
No wind so this was false
Weight- the can might be too heavy to make it from where you throw from:
Weight didn’t matter. A golf ball hit the ground the same time the car did.
2. Name at least two things that surprised you about projectile motion after performing the test.
1. That the car and golf ball hit the ground at the exact same time
2. That weight has no effect on whether one object hits faster than another
3.
Draw a picture of a typical path of a projectile. Label all the key terms, including any necessary
explanations
4. You should have found that launch angle is a key variable.
a. What angle causes the largest height?
90 degrees was the largest height because it was straight up
b. What angle causes the largest range?
45 degrees was the largest range because it was half the largest height’s launching angle