Science Fair: Bridges

Table of Contents

Abstract………………………………………………………………………………………………………………………………………2

Background Information……………………………………………………………………………………………………………...3

Question……………………………………………………………………………………………………………………..………………4

Variables…………………………………………………………………………………………………………………………………….5

Hypothesis………………………………………………………………………………………………………………………………….6

Materials…………………………………………………………………………………………………………………………………….7

Procedure…………………………………………………………………………………………………………………………………...8

Observation/Results……………………………………………………………………………………………………………………9

Conclusion………………………………………………………………………………………………………………………………...10

Bibliography……………………………………………………………………………………………………………………………..11

Acknowledgement Page…………………………………………………………………………………………………………….12

Abstract

This science fair project was to see which design of bridges made out of popsicle stick can hold the greater amount of weight. Architecture has design different bridges, depending on the use of the bridge and the nature it is built in. Three bridge designs was constructed and were put to test to see which one could hold more weight. Therefore, the experiment was to see which design of bridge should be considered to save on the material and money.

The material used for the science fair were 180 popsicle stick, wood glue, two chairs, a bucket, pieces of strings, household item (used as weight), weigh scales and a camera. For the experiment, a bridge, each containing sixty popsicle stick, were placed on two chairs, then a string were attached to a bucket and then put on the bridge, then weights or household items were put in the bucket. When the bridge completely broke, the items were added up. Pictures were taken before, during and after the experiment.

Each bridge had a bending point except for the third design. The reason is due to the structural design. The first bridge held 2520 grams and started to bend at 1170 grams. The second bridge held 6570 grams and started to bend at 5690 grams. The last bridge held 7840 grams and did not bend. So the bridge that should be use at more often is design three.

Background Information

A bridge is a structure built usually over bodies of water, valleys, or roads. The purpose of a bridge is to provide passage over the obstacle. Designs of bridges vary depending on the function of the bridge, the nature of the place where the bridge is constructed, the material used to make it and the amount of money the architect has.

History Bridges

The first bridges were actually made from nature – like a fallen log across a stream or with stones in the river. The first bridges made from humans were using the ideas that nature had provided and probably used logs or planks across a stream and eventually stones, using it for support and a crossbeam arrangement. Until the end of the 18th Century, bridges were made out of timber, stone and masonry. Nowadays bridges are built out of concrete, steel, stainless steel or combinations of those materials. The first bridge make out of iron was The Iron Bridge constructed in 1779.

Question

Which design of bridges can hold the greater amount of weight?

Variables

Independent Variable – Having different design of bridges.

Dependant Variable –The amount of weight the bridge can hold.

Constant Variables –

Same number of popsicle sticks in one bridge Same type of glue Same bucket use for the experiment

Hypothesis

If the third design is tested, then the bridge will hold the larger amount of weight.

Materials

180 popsicle stick(60 per bridge) Wood glue* 2 chairs 1 bucket Strings* Household items* 1 weigh scale 1 camera

* = unknown amount.

Procedure

1. Gathered all materials.

2. Counted 60 popsicles per bridge design.

3. Glued them together with wood glue.

4. Took pictures for each bridge.

5. Measured each of the items.

6. Put new strings for holding the basket for each bridge to ensure that the string wouldn’t break because it has too much stress on it.

7. After each weight that was put on, and then took picture to see how much was bent.

8. Repeated the procedure for each bridge.

Observation/Results

For the first bridge, it held a total of 2520g or 2.52kg before it broke. The bridge started to bend when 1170g or 1.17 kg was put on.

The second bridge held 6570g or 6.57kg before it snapped. This design bridge started to bend when 5690g or 5.69kg was put on the bridge

The last design of bridge held 7840g or 7.84kg before it got destroyed. It did not show signs of breaking.

Conclusion

After doing the experiment, the third design held the most weight, which then proves that the hypothesis was ultimately correct. During the experiment, the first and second design withheld a good amount of weight before it showed signs of bending then it officially broke after a few other items were placed onto the weight. For the third design however, it did not show any signs of bending due to the initial structural design. Even though it did not show any signs of bending it did not mean that it will break easily, it was actually the bridge that showed the most amount of endurance before it broke. In the end, design three held the highest amount of weight containing 7840 grams of different household items before it broke.

Bibliography

http://en.wikipedia.org/wiki/Bridge

http://myjwill.com/?page_id=78

Acknowledgement Page

I want to thank my sister Lo-Lo for all her help and organization throughout this project. You help me a lot and I couldn’t do it without you!