What it shows
A crew capsule coming back from space is slowed by a parachute and lands softly. A larger parachute canopy gives more air drag and a slower fall, which protects the passenger.
The science
Falling objects speed up until the upward air drag matches their weight. A wide canopy catches more air, so the drag is larger and the final speed is lower. The padding in the capsule stretches the time of the final stop, which reduces the force on the passenger.
Materials
Cost: under Rs 50. Many items come from home or from waste; spare parts such as LEDs, motors and wire are in the store.
- A plastic bottle or a paper cup as a capsule
- A thin plastic bag or cloth cut into a circle or square
- Thread for the strings and tape
- A boiled egg or a small ball of clay as the astronaut
- Cotton wool or foam for padding
- A stopwatch and a measuring tape
Safety
For this project: Drop only from a safe height such as a first-floor balcony railing with an adult, and keep people away from the landing zone. Use a hard-boiled egg to avoid mess.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesStep by step
8 steps. Do them in order, and test each part before you go on to the next. Write what you notice in a notebook as you go.
Cut parachute canopies of three sizes: 20 cm, 30 cm and 40 cm wide.
Tie four threads of the same length to each canopy at equal spacing.
Tie the other ends of the threads to the capsule.
Pad the capsule with cotton and place the egg inside.
Drop from the same height for each canopy size, three times each, and time the fall.
Note which canopy gives the slowest fall and check the egg after each landing.
Calculate the average falling speed as height divided by time.
Plot canopy size against average fall time on a graph.
What you should see
The larger canopy falls more slowly and the egg survives, while a drop without a parachute usually damages it. A graph shows a clear trend of slower falls with bigger canopies.
Viva questions
A teacher or a judge will ask how it works. Try to answer each question before you open it, then compare.
1What is terminal speed?
The steady speed when air drag balances weight.
2Why does a bigger parachute fall slower?
It catches more air and gives more drag.
3Why add padding?
It lengthens the stopping time and lowers the force.
4How do real capsules land?
With several parachutes and then a splashdown or a soft ground landing.
Take it further
Cut a small hole at the centre of the canopy and test how it affects stability.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
Science projects
Physics Working Models Explained
Twenty classic models, how each works and how to make it
Science projects
Science Projects for Class 6 to 8
Working models matched to middle-school science topics