The relationship between the shape of a parachute and its drop velocity
The materials required for this science fair project are as follows:
- 4 plastic bags that each have a surface area of at least 500 square centimeters
- 15 threads that each are about 400 mm long
- 4 washers that have a weight of about 5g each
- a measuring tape
- a stopwatch
- an assistant
- a building with a balcony on its second floor
1. For this science fair project, the independent variable is the shape of the parachutes’ canopies. The dependent variable is the drop speeds of the parachutes. How long does it take for the parachutes to reach the ground? Measure this using a stopwatch. The constants (control variables) are the surface area of the canopies, the weight of the nails, and the height from which the parachutes are dropped.
2. Cut a triangle, a square, a rectangle and a circle from 4 plastic bags. Each shape should have an area of 500 square centimeters. Calculate how long the sides and diameters of the shapes should be, before cutting them out.
3. Punch 3 holes in the corners of the triangular canopy. Punch 4 holes in the corners of the square and rectangular canopies, and 4 holes in the round canopy. Tie 1 end of the strings to the holes in the canopies and the other end of the strings to the washers.
4. With the help of an assistant, measure the length of the distance between a balcony on the second storey the building, and the ground. Use a long measuring tape. This distance shall be the drop distance.
5. Have your assistant drop the parachutes from the balcony while you wait downstairs with the stopwatch. At the same time, ensure that the parachutes do not land on passersby.
6. Calculate the drop speed of the parachute and record in the table below. Use the formula below:
Drop speed = distance traveled / time taken
Scientific Terms and Concepts:
Gravity, drag, force, air resistance, velocity
Basic safety requirements. Adult supervision recommended.