Bridge that gap

Investigate the best bridge design.

The challenge is to build a bridge across a 30 cm gap that is strong enough to support an object of mass 250 gm at its central point.  You must investigate different ways to build such a bridge - using only paper (plus incidental materials such as glue, sticky tape, etc.).  Then you must decide which is the best method - based on factors such as (a) amount of paper used (b) how easy it is to make (c) how strong it is (d) appearance.  (You may decide to use additional factors.)

Be careful with scissors!

PLAN

Suggest a variety of methods.

Try out some of these ideas before you get started properly.

Decide on the best 3 or 4 methods to investigate fully.

It may be best to work on each design in turn - or you could decide to have different teams working on several designs at once.

I WILL NEED

Paper.

Glue and sticky tape.

A 250 gm weight.

I MAY NEED

Various other "bits and pieces".

FAIR TEST

Decide on some simple guidelines about what extra materials you can use.

You might decide to spend equal amounts of time on each design.

Perhaps you should decide on a scoring system before you start.

PREDICTION

Which design do you think will be strongest?

Which design will be easiest to make?

Which design will look most attractive?

PRACTICAL ACTIVITY

Try not to turn this investigation into a competition as it will lead to a biased and unscientific approach.

Even if you have decided to limit the amount of time spent on each design, try not to rush.  Your investigation will not be a fair one if it is spoiled by shoddy workmanship.

COLLECT

DATA

How much paper did you use in each design?

What other "bits and pieces" did you use?

How long did you spend on each design?

Which design is strongest?

ANALYSE

DATA

Use a scoring system to decide which design is best for each of the factors.

PRESENT

FINDINGS

Your presentation could include -

• diagrams of the different designs;

• lists of materials used (and amounts) for each design;

• the completed bridges;

• photographs of the finished bridges;

• the scores awarded for each factor;

• a brief comment on each design.

EVALUATE

INVESTIGATION

If you have carried out this investigation, click the icon to send in your results to Brainboxx and we may publish your work on the website.  It is best to e-mail the results of your investigation or you may need to send them by post.  Make sure you get permission from a teacher, parent or other adult before you get in touch.

Bridgebuilding interactive