Define& inquire

Request(task): Design and make a toy that converts energy.

Design and make a device that can be used to teach energy conversion.

Target audience: anyone who wants to look at energy transformations directly in an interesting way, but the main audience will mostly be high school students who have the ability to understand how energy transferring works.

Things that need to be considered(design problems):

1. It should ALWAYS BE SAFE. 

2. the process of transferring energy should be clear and easy to understand.

3. We’re making a ‘toy’; it should be entertaining.

Precedents 

Explanation 

Pros 

Cons 

https://www.youtube.com/watch?v=Jw9n_KbxvqA

this infinite marble loop rail converts the battery’s potential chemical energy to kinetic rotational motion, then convey the kinetic energy to the marble, which makes the rotational motion into linear motion and shoots the marble again to the top of the marble rail. 

It looks cool, and the conversion can be easily seen.

It’s too hard to build; I need to 3d model and print everything or have an extremely precise model using math formulas that I don’t even know.

https://www.youtube.com/watch?v=8DgCcYbs9JQ

Rollercoaster converts position(potential) energy into kinetic energy, and it also uses the opposite.

A rollercoaster is a most commonly used example to show energy conversion. It shows both ways of transfer.

But it’s way too common.

https://www.youtube.com/watch?v=b7zWwo9dbiU

Mouse trap cars use the potential energy held in the spring in the mousetrap, transfer the energy into kinetic energy, and move the car.

It’s a really good way to visualize the conversion; It moves a very long distance if well-made.

We don’t have mousetraps or any alternatives for the parts. But since this was the most unique and relatively easy thing to make, We tried to find alternatives. 

https://www.youtube.com/watch?v=WLu2Eols0BI

This rubber band car was the alternative we found. It uses the same function as the mousetrap car; potential to be kinetic, but it uses rubber bands instead of springs. 

This should be the alternative that’s most close to a mousetrap car.

It became too easy and doesn’t look very good, but we don’t have enough classes.

Final Defining of the design(success criteria): A Rubber band car that has high efficiency, by using the information that was on precedent #3 about the ratio of the wheels.