Crosswinds and bridge stability
The materials required for this science fair project are:
- 1500 toothpicks
- 6 pairs of disposable chopsticks
- 1 box of clay
- 10 meters of string
- Letter sized paper
- 1 pair of scissors
- 3 bottles of glue
- 3 transparent protractors
- An industrial fan
1. The independent variable for this science fair project is the type of bridge used – open sides, 50% side coverage and 100% side coverage. The dependent variable is the tilt of the angle of the bridge deck caused by the force of wind from the fan. This tilt angle is measured using a protractor placed on the bridge. The constants or control variables are: the speed of the wind from the fan, the length of the bridge, the width of the bridge and the weight of the bridge.
2. Figure 1 above is an illustration of the model bridges that you will need to construct for your science experiment. . The deck of the bridge is constructed using 500 toothpicks. The toothpick can be fixed onto the string using glue or by tying knots. The frame at the sides of the bridge can be made using strings and toothpicks. The paper should be cut according to the measurements required to cover the sides of the bridges up to 50% or 100% as shown in the figure above.
3. The first bridge with the open sides is placed at a distance of 1 meter from the industrial fan. The sides of the bridge are made to face the fan. Clay is used to secure the bridge firmly onto a flat surface (ie: table).
4. The motion of the bridge caused by the force of wind produced by the industrial fan is observed. Using the protractor, the angle of swing or tilt of the bridge is observed and recorded in the table provided below.
5. Step 4 is repeated using bridges with 50% covered sides and 100% covered sides respectively. Similarly, the angle of swing or tilt of the bridge is observed and recorded in the table provided below.
Basic safety requirements