In the sport of skydiving, a person jumps out of an airplane from a very high altitude, flies through the air, and releases a parachute to help them fall safely to the ground, as shown in Figure 1. The parachute slows down the skydiver’s fall so that they can land on the ground at a safe speed. How does the parachute do this?
As the skydiver is falling, the force of gravity is pulling the skydiver and their parachute towards the earth. The force of gravity can make an object fall very fast! The parachute slows the skydiver down because it causes air resistance, or drag force. The air pushes the parachute back up, and creates a force opposite to the force of gravity, slowing the skydiver down. As the skydiver falls slowly to the earth, these “push and pull” forces are nearly in balance.
In this aerodynamics science project, you will test whether the size of the parachute is important for slowing down the speed of the fall. You will make a series of parachutes from small to large and test how quickly they fall from the same height. Will the large parachutes fall more slowly than the small parachutes?
Terms and concepts
- Parachute
- Gravity
- Air resistance
- Drag force
- Surface area
- Load
Questions
- How does a parachute work?
- How will increasing the diameter of the parachute increase its size, or surface area?
- Do bigger parachutes have more air resistance, or drag force, than smaller parachutes?
- How do you think the amount of drag force a parachute has will affect how well it works?
Materials and equipment
- Heavy weight garbage bags
- Metric ruler
- Scissors
- Light weight string (at least 6.4 m, or 21 ft)
- Washers (4) and twist ties (4) or pennies (8) and tape
- A safe, high surface about 2 m from the ground. A good place for your test might be a secure balcony, deck, or playground platform.
- Stopwatch, accurate to at least 0.1 sec
- Optional: Helper
- Lab…
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