Motion Simulations
Today you will be using a number of motion simulations from the University of Colorado’s PhET website.
All of the simulations we will be using can be found at:
http://phet.colorado.edu/en/simulations/category/physics/motion
To begin each simulation click the “run-now” button. When you are done with one simulation, close its
window before opening the next simulation, otherwise they may begin to slow your computer down
(and they don’t have that much speed to begin with). Answer the numbered questions on a separate
sheet of paper.
Ladybug Motion 2D
http://phet.colorado.edu/en/simulation/ladybug-motion-2d
In this simulation there are 3 ways to move the ladybug.
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You can click and drag the ladybug directly
You can have the program move the ladybug with linear, circular, or elliptical motion
You can use the “remote control” in the lower right corner
See how well you can draw a circle using the click and drag method, then under the “Choose Motion”
options select circular.
Pay attention to the velocity and acceleration vectors.
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What happens to the magnitude of the velocity vector as the ladybug moves in a circle?
What direction does the velocity vector point in?
What happens to the magnitude of the acceleration vector as the ladybug moves in a circle?
What direction does the acceleration vector point in?
While the ladybug is still moving in a circle select the “linear” setting from the “Chose Motion” options.
Try to change the motion to linear while the ladybug is moving diagonally. Notice how the ladybug
bounces off the walls.
5. When does the ladybug experience acceleration?
6. Write a rule that describes what direction the acceleration acts in based on your observations.
Now select manual motion.
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With the remote control set to position, click in the remote control box and try to get the
ladybug to move in a perfect circle.
Set the remote control to velocity and try to get the ladybug to move in a perfect circle
See how well you can draw a circle with the remote-control set to acceleration
7. Did you find it easy to control the ladybug using the remote control? When was it easiest?
When was it the hardest? Did you ever lose the ladybug off the screen and have to use the
“return ladybug” button?
Once you can manage some control of the ladybug you are ready to move on to the next simulation.
Maze Game
http://phet.colorado.edu/en/simulation/maze-game
First of all, before you do anything else with this simulation, turn the sound off. Then confirm that the
sound is off. Next ask yourself; “Is the sound off?” and if the answer is, “yes” you are ready to proceed.
At this point it is important to leave the sound off while using this simulation.
In this simulation your goal is to move the red ball to the finish point using the remote control. Like the
ladybug, you can control the ball’s position, velocity, or acceleration. After spending a few minutes to
practice you skills select level 1. This brings up a wall that you must avoid as you move the ball to the
finish point. When you are ready click the “start game” button and move the ball to the finish point. If
you hit the wall you must reset the game and begin again. If you reach the finish without touching the
wall you will score a goal and the timer will stop.
8. Play the maze game on level 1 and level 2 using position, velocity, and acceleration to control
the ball. Record your best time for each setting (so you should have 6 times recorded).
If you have time you can attempt to become the All-State Maze Game Universal World Champion of
Mr. Rose’s Physics Class by completing the “certain death” level in record time using acceleration to
control the ball.
Moving Man
http://phet.colorado.edu/en/simulation/moving-man
When you open this simulation select the “Charts” tab at the top of the screen. Watch what
happens on the charts if you click and drag the man.
Try moving the man with constant velocity from one side of the screen to the other. Next, see if
you can move the man with constant acceleration.
You can also set the values by typing them into the boxes next to the charts.
9. Place the man at the tree (position = -8 meters) and set the numerical value of his initial velocity
to the number of letters in your first name. (For example, Larry would choose 5 m/s to be the
initial velocity. Find the value of acceleration that will cause the man to come to rest in from of
his house.
10. Double the value of the acceleration you found in #9 and find the initial velocity required to
cause the man to move from the tree and come to rest in front of the house.
11. Divide the value of the velocity you found in #10 to the value of velocity you used in #9. What
do you get? What do people around you get for this problem? Can you explain these results?
Other Simulations
12. When you are done these three simulations, select at least two other motion simulation from
PhET. Describe what you could control, and what concepts were demonstrated in these
simulations as well as what you found interesting about them.