- Parachutes enable people to land safely on the ground after they have evacuated from an airplane, helicopter or balloon. Parachutes work because of gravity and air resistance.
- Gravity is a force that attracts things on earth to stay on the planet. When an object comes out of a plane, for example, it will always fall towards the earth's surface. A parachute also obeys the laws of gravity, moving downwards until it lands.
- The neat thing about parachutes is that they do not fall quickly. This is because of their surface mass. When the person wearing the parachute steps out of the plane, they begin to fall. At a predestined level of height, the person activates the parachute, causing it to open. When the parachute opens, its fabric expands and drag, or air resistance, is created. The parachute and person will continue to fall towards the earth, but their descent is rapidly slowed. This drag allows the falling person to land safely.
- Without air resistance, all objects would fall at the same rate, no matter if the object was a person, rock or feather. For example, a rock falls faster than a feather because it has more mass and is heavier. The rock can easily move through the air because its weight enables the rock to push air particles out of the way quickly. On the other hand, feathers are light and therefore unable to move air particles effectively. This is why a feather will float around for quite some time before it lands. The feather traps air while the rock does not.
- The construction of a parachute is thin material that covers a large area when opened. Air particles are trapped within the material. The trapped air makes the parachute balloon up and outwards, stretching and filling the fabric. The person attached to the parachute plays a part in the air resistance, as well. Their weight helps to work with the drag principle. This means that if the falling object is very light, there will be no resistance created (like the feather). The weight of the person combined with the trapped air in the parachute enables the fall to happen.
- If a person were to jump from an airplane and not have a parachute attached, they would quickly fall, just like the rock. People are heavy enough that the air particles would be quickly pushed out of the way as the person descended. If the person is attached to an open parachute, however, the air particles now have a huge surface area to fill. The larger the parachute, the more air particles it can catch.
