Modeling Motion with Algodoo: Level 1

Algodoo is the most powerful, flexible and fun piece of physics software ever created.  It requires much of the same type of programming used in many of the most popular computer games. You can have a lot of fun with it, and a quick YouTube search of Algodoo will present you with many ‘scenes’ of mind-boggling complexity (too much time on their hands??).  But most importantly, Algodoo will allow you to learn physics in ways not previously possible.   It can do this in several ways:

• Allows an (almost) infinite range of masses, velocities, forces, distances, etc. (You can’t do that in real life!)
• Plots anything you want (speed v. time, acceleration v. time, momentum v. time, kinetic energy vs. height, etc. etc.) in real time

We will use Algodoo throughout the rest of the course.  The main purpose of this assignment is for you to get comfortable with the program, in particular….

## Skills Checklist

• Creating objects
• Round (hello, rolling!)
• Square (hello, sliding!)
• Fixing objects
• To the background (so they don’t move)
• To other objects (so they move together)
• Changing coefficients of friction
• Allows for “theoretical” conditions (goodbye, friction!)
• Plotting graphs
• Distance vs time
• Speed vs time
• Annotating graphs (hopefully using Skitch or other flexible image annotation tool)

I would highly recommend completing at least 1 tutorial. To access the tutorials, click on the question mark (?) in the top menu bar (top left).

To beat each of the following levels, you will need to satisfy the requirements and prove it with:

• A screenshot of your scene.
• Make sure it’s large enough to get an idea of what is going on.
• An annotated* graph produced by the object (this part is most important!).
• Make this as detailed as possible.  All features of the line should be explained.
• A short written analysis of how your graph proves you’ve beat the level.

*I highly recommend you download and install Skitch, a simple image editing program (which, for you Evernote users, syncs very well with Evernote)

# EXAMPLE:  Level 0:  A moving object:

Scene:

Annotated Graph:

Analysis:

Motion is defined as a change in position over time.  The blue ball shows motion in two axes, both X and Y.  This motion is shown by the graph, because the X-axis line has a non-zero slope the entire time, meaning it is changing its position the entire time.  The Y axis, however, shows non-zero slope only during the first ~2 seconds, since it hits the bottom of the ramp, which causes it to stop moving in the “up-down” axis.

Tips:

Right clicking is your friend.  Almost all of the variables you will want to change (i.e. mass, friction) are done so by a drop-down menu when you right click.  Also, this is where the option for plotting a graph is hiding.

The Challenge:

You will work in pairs and submit one document between the two of you (it is a Google Doc that has already been shared with you and is in your drive, similar to the Measuring Speeds Lab).  I would recommend both people have Algodoo running, with one computer acting as a “scratchboard” and one as “final draft”.  Eventually, you’ll need to add screenshots to this Google doc.  (note--you’ll delete all of these instructions once you are finished)

Scene

Annotated Graph

Written analysis

Scene

Annotated Graph

Written analysis

Scene

Annotated Graph

Written analysis

## Level 4: An object moving at a constant speed, then changing speed.

Scene

Annotated Graph

Written analysis

When you are finished, you will find another group that is also finished.  Working as a group of 4, answer these questions:

1. How did the two groups achieve constant speed?  If you both chose the same method, try to come up with another way.
2. What was the most challenging part of this assignment?
3. Identify one major difference between your scene for Level 3 or 4, and their scene for Level 3 or 4.

Remember to delete everything above “The Challenge” once you are finished.

## Extra levels

• An object that moves exactly 1.0 (+/- 0.05) meters per second for at least 5 seconds.
• An object that moves at speed A in one direction, then speed B in the opposite direction (speeds A and B must be different).
• An object that is able to move uphill.