Summer Science Camp: Slow Car Race

Students are each given a length of lumber (the size doesn't really matter, just make sure everyone has the same sized piece) and a matchbox car.  They need to create a ramp the car can travel down, but as slowly as possible. 

The students can position the wood in any way they wish and add anything to the wood to slow the car.  My only caveat is that they cannot ruin the wood - at the end of the "race" they need to be able to remove anything they've added and return it to me in the same condition in which they were given it (so it can be used again for another group). 

I spread out a variety of supplies:

• a variety of types of paper
• rubberbands
• masking tape
• glue
• yarn
• string
• thread
• toothpicks
• popsicle sticks
• straws

Students are welcome to ask for other supplies - if it's something I have in the lab, they're welcome to use it. 

The ramp construction must be completed within one session.  Even students who build quickly can remain busy by constantly testing and trying to improve upon their design.

Once construction is complete, all the ramps are set up.  The cars are placed at the top of the ramp and released at the same time.  The last car to reach the bottom is declared the winner.  Any cars that don't reach the bottom of the ramp (put a 5 or 10 minute time limit on the race) are disqualified from the competetion.

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Friction: Give Yourself a Hand

No surface is perfection smooth – they all have bumps of ridges to a various extent.

Friction occurs when two surfaces rub against each other and those bumps and ridges catch on each other.

A notable by-product of friction is heat.

Have your students rub their hands together quickly. It doesn’t take much hand rubbing to notice a warm feeling.

Now put a small squirt of lotion (stick to unscented stuff for this) in each students hand.

Have them rub their hands together again – much less heat is generated.

The lotion acts a lubricant – it helps fill in some of the bumps and ridges on the surface of the hands, resulting in less friction and therefore less heat.

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Presented at the 2003 New Jersey Science Convention.

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Friction: Phone Book Friction

This one takes some prep work (you might want to find some student “volunteers” to help you out), but it’s a fun one!

You’ll need two phone books – the larger the better.

You need to shuffle the pages of one with the other. I wish I had a brilliant technique to share with you on how to do this, but I don’t. Do what works best for you. It doesn’t need to be perfect, but the more pages you get interspersed, the more effective.

Now that the books have been joined together as one, have two students attempt to play tug-of-war and pull them apart.

Ha! They can’t do it! Too much friction!

No surface is perfection smooth – they all have bumps of ridges to a various extent. Friction occurs when two surfaces rub against each other and those bumps and ridges catch on each other.

Each of the pages of the phone book has two surfaces filled with ridges and bumps. And, if you’ve done a good job shuffling those pages, there are a whole lot of surfaces trying to slide past one another. Whole lot of pages, whole lot of surfaces, whole lot of ridges and bumps, whole lot of friction!

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Presented by Daryl Taylor at the New Jersey Science Convention.

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