Paper Bridge Science Project

With only a few weeks remaining in school I’m breaking out all of the fun activities.  This one is no exception.

The objective of this activity is to build a paper bridge that can withstand the most mass without breaking.  It’s dirt cheap to do and you probably already have the supplies in your classroom.

Materials for each group:

1. 3 pieces of standard size copy paper
2. 1 foot of tape (masking or scotch would work)
3. 1 ruler
4. 1 pair of scissors

At the beginning of the class I explain to the students that they are going to build a bridge with the given supplies.  I then show them the apparatus that I will be testing their bridge on.  I use 6 textbooks that have a valley in-between of 19cm (3 books on each side).  I also explain to them that the height of the books is 10 cm.  These two pieces of information are critical in order for the students to build a bridge that fits.

I setup a couple of testing stations throughout the room so that they can measure their bridge as they are building it, but I do not let them add the gram-stackers that I will use for the mass on top of the bridge.

There are a couple of other rules that I give them before I let them work on their bridges

1. You cannot tape anything to the books
2. You cannot use the ruler or scissors as a part of your bridge
3. Once the bridge starts to fall it’s done and I will stop measuring
4. You can cut the paper

At first you will have students that think it can’t be done but after several minutes you’ll see some bridges start to take shape.  One pitfall they seem to all have is that they think tight, skinny supports are better for the bridge than large, wide-ones.  The skinny supports fell over in almost every bridge I tested.

The winning bridges in my class all had the same attributes.  They had a series of well-placed large support columns holding it up.  The world record in my class held all 1000g that I was using, plus a box of scissors, plus a backpack.  It was great.

I’d love to see pictures of your bridges if you end up doing this in your class.  Leave them in the comments or email them over to me.