Toothpick Bridge Activity

Period 2Ms. Buenconsejo

Andrea, Francisco, Yo Woon

Introduction The objective of this project is to build a bridge

with using only toothpicks.

After we build the bridge, we are to test its strength by making it carry items that vary in weight.

We believe that if we include the shape of the triangle into our diagram and make it to a “teepee” style, we’ll be able to successfully make a bridge that’s able to handle more than 2kg of an item.

The Challenge STANDARD1. Investigation and Experimentation2. Forces and Motion LEARNING OBJECTIVES1. Design and Construct Toothpick Bridge2. Use Measurement for Experiment3. Explain the Physics of the Bridge PROBLEM What kind of design or strategy will make a bridge strong

enough to hold at least 2 kg mass? HYPOTHESIS If we make a bridge with a triangular arrangement (Truss

Bridge), the bridge would be strong enough to hold at least 2kg mass.

Blueprint Materials Plan

/ Design+ Toothpicks+ Ruler+ Glue Gun

Procedures

First, we measure how long the bridge would be. Not too

long, not too short. It is 40cm. long. Next, we start

arranging the toothpicks into

triangles. This would be the side.

Procedures

We then duplicate one of the sides to

make the other.

After we finished both

sides, we made the

base. ->

We glued the sides together by

the top, then glued the base to

both sides.Ta-Dah~

ProcedureWe needed to

reinforce the bridge, so we added more toothpicks. Most of them in the corners and in this middle.

Finished Product!

Procedure

The bridge had no problem holding the first 500g of

weight, nor did it have any problems with 2000g…

…when it came to the last extra weight of 500g, that’s when it started to break. It

was able to hold 2500g in 13 seconds.

Data & Observation Bridge

Data

How long was the bridge? 40 cm.

How wide was the bridge? 5cm.

How tall was the bridge? 6cm.

How much weight had the bridge held?

2500g

To test how strong the bridge was we had to make it carry weights.

The weights were, small bars. One bar= 500g.

The objective was to construct a bridge that was able to carry at least 2kg.

(1000g= 1 kg)The bridge was able to carry five bars, which is equivalent to

2500g.

Data & Observation

These are good examples of Truss Bridges. We based our bridge to this design.

These designs specifically.

Physics of Bridge As stated in Newton's Third Law of Motion, it is not possible for a single

force to occur because every action has an equal and opposite reaction. Engineers must consider this law of motion when they design a bridge because the bridge will react to wind, moving vehicles, or even earthquakes

For all forces acting on a bridge, there must be a counter force pushing or pulling in the opposite direction.

These forces are defined as either compression or tension forces. A force of tension will lengthen or pull on a material while a compression force will squeeze or push a material together.

A bridge member under tension, compression or both forces at the same time experiences what engineers define as stress.

The elongation or shortening of a material under stress is defined as strain.

Engineers must keep in mind that certain materials are better under compression rather than tension.

Some materials such as steel, flexible yet strong can carry tensile forces. There are also materials that can carry both tensile and compressive

forces. Pre-stressed concrete is one of these materials. Pre-stressed concrete has steel rods running through it so it can withstand

not only a compression force but a tension force as well.

Summary & Conclusion In conclusion, our hypothesis was correct. If we make a bridge with a triangular arrangement (Truss

Bridge), the bridge would be strong enough to hold at least 2kg mass.

Bridges gain their strength through the triangular arrangement of their beams.

When you arrange the toothpicks into triangles and fit the triangles together, you are increasing the structure of the bridge and its ability to bear heavier loads.

The tighter the triangles are, the stronger the bridge is. You can also achieve more strength by reinforcing the

triangle frame with other triangles. The bridge had no problem with 500g. It was able to reach the desired weight of 2kg. It was even able to carry 2500g, but for only 13 seconds.

ReflectionThis project was very interesting to do because we

were unsure if 100 toothpicks would be enough to make a strong bridge that was able to hold at least 2kg mass. In addition to that, we had restrictions.

The bridge should be free standing while it is tested on a flat surface. Only toothpicks are to be used. We cannot cute the toothpicks. Excessive amount of glue was not to be used as part of the structure.

It was difficult at the beginning since we didn’t know where to start. But one thing we did know was that we had to include as many ‘triangle’ shapes as possible. Another problem was keeping in mind the excess of the glue.

In the end, I’m glad our hypothesis was correct and we were able to solve the problem. With the truss bridge design, we made a bridge strong enough to hold 2500g!

Safety Lab Rules We could only use the materials

given to us and do what the teacher has instructed

We had to focus on the project at hand, so we couldn’t play around or daydream.

We were using a glue gun. So we had to keep in mind that we were not suppose to not point the glue gun in anyone’s direction so to not burn them by accident.