How the Bernoulli's principle works for different shapes
The materials required for this science experiment are as follows:
- a fan
- 3 treads that are each about 400mm long
- 3 sheets of light but stiff cardboard
- a roll of scotch tape
- a ruler
1. For this science project, the independent variable is the shape of the objects used in this experiment. The dependent variable is the amount of air lifton the object. This can be ascertained by measuring the heights to which the objects are lifted, using a ruler. The constants (control variables) are the wind speed, the depth or width of the objects and the weight of the objects.
2. Cut 3 strips of cardboard to approximately 50mm x 150mm. Bend these strips to form the 3 shapes shown in figure 1 above. Use a roll of scotch tape to stick the 2 ends of the strips together.
3. Measure the distance between the floor and the center of a fan.
4. Put a string through the gap in object 1 (an airfoil) and tie both ends to the fan’s front frames.
5. Switch on the fan and watch the airfoil float. Measure the length of the distance between the rear the object and the floor, and deduct this from the distance measured in procedure 3. Record the result in the table below.
6. Repeat procedures 4 and 5 with objects 2 and 3.
Note: The Bernoulli’s principle should cause the objects to float. However, the objects will also be dragged down by their weight. If a strip of cardboard is too thin or flexible, the wind will blow the cardboard out of shape. Use Experiment with strips of cardboard that have different thickness and weights in order to obtain the desired results.
Basic safety requirements