A parachute is an umbrella-like device for slowing the descent of a body falling through the atmosphere. Separate panels sewn together form a canopy attached by suspension lines to a harness worn by the user. Originally designed to provide a safe escape from a disabled aircraft, parachutes are also used for dropping supplies and for slowing returning space capsules.
In this experiment, we will find out if the size affects the speed of a falling parachute.
Things Required:
Small plastic garbage bag
String 2 small
Washers
Scissors
Ruler
Directions:
Cut eight separate strings about 20 inches (50 cm) long. Cut a 12-inches (30 cm) square from the plastic. Tie a string to each comer of the plastic square. Tie the four free ends of the strings together in a knot. Be sure the strings are all the same length. Use a string about 4 inches (10 cm) long to attach the washer to the knot in the parachute strings. Make a larger parachute using a 24-inches (60 cm) square of plastic and the four remaining strings. Attach the washer to the parachute with a 4-inches (10 cm) piece of string as before. To test the parachutes, hold each in the centre of the plastic sheet. Flatten the plastic. Fold the plastic in half. Loosely wrap the string around the folded plastic.
Throw the parachutes up into the air one at a time, and observe the time it takes for each to reach the ground.
This Is What Happens:
The larger parachute opens and floats to the ground more slowly than does the smaller parachute.
Science Behind It:
Objects push against air as the force of gravity causes them to fall. This upward push of the air molecules is called air resistance. Objects with a large surface, such as the large parachute, have more air resistance. If the object has a large surface and a small weight, the upward push of air can equal the downward force due to weight, causing the object to gently float downward like a feather. Some insects have such a small weight as compared to their surface area that instead of falling from a height, they float down and, therefore, are not harmed.
