Evan McKenna and Stephan Strok STEM MARBLE RUN Evan McKenna and Stephan Strok

The problem How long can we keep the marble in the marble run?

Gravity To understand how the marble moves we first have to understand how gravity works Gravity, or gravitation, is a natural phenomenon by which all things with mass are brought toward (or gravitate toward) one another

How gravity affects the marble Now that we know that gravity is, time to start making the marble run. So if we want to accelerate the marble we need to slope the track downwards and if we want to slow it down we need to build a bump. See diagram on next page:

Diagram To speed up the marble we need a downward slope, here's how it works: To slow down the marble we need to slope the track up:

Here is an example of gravity being used in a marble run

Friction To slow down a marble we can also use friction to our advantage. Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

Example of friction An example of friction would be if you are pushing a heavy box. It is hard for two reasons: The box is heavy Friction. The box is rubbing against the ground which creates friction. Usually this is bad but it can help our marble run. If you don’t want to create a bump on your run, you can use sandpaper or any other material that causes friction to slow down the marble

Marble Run So now that you know what gravity and friction are and you know how to slow down and speed up a marble, you should be able to build your own marble run but we will still provide an example. Materials : kitchen roll, cereal box, duct tape and a marble (obviously!).

Final Diagram and example

Explanation of Diagram On the previous page, we drew a diagram of a simple marble run and provided an example of a homemade, simple but effective marble run. As you can see on both marble runs, they start of with a downward slope to accelerate the marble and bumps and ramps to keep it at a reasonable speed. We also used friction (underlined part is sandpaper)to slow down the marble.

Conclusion And that, ladies and gentlemen, concludes our presentation about physics and how to build a marble run! Thank you for your attention! Any questions?