Thursday, June 28, 2012

How does a Parachute Work?

            A parachute is an umbrella like device used for slowing the descent of a body falling through the atmosphere. Originally, it was conceived as a safety measure for a fighter pilot in a flying aircraft. Now parachutes have wide application in times of war and peace; for example, they are used for safe dropping of supplies of essential items in times of emergency as well as for landing of personnel.


            The first man to demonstrate the use of parachute was Louis Sebastian Linesman of Franc in 1783. André Jacques granaries was first to use a parachute on regular basis demonstrating a number of exhibition jumps including one from a height of about 2400 meters in England in 1801.

            Early parachutes were made of canvas and later silk was used. Captain Albert berry of the U.S. army made the first successful descent from an aero plane in 1912. in world war II, parachutes were used for a variety of purposes i.e. landing of special troops for comber infiltrating agents into enemy territories and dropping of weapons, etc. parachutes are made of nylon and are generally about 7 to 9 meters wide, when open. Parachutes used for dropping heavy cargo may be as wide as 30 meters when open.

            Now the question arises how doe s a parachute works?

            A parachute operates on the simple principles involving the force of gravity and air resistance which are the two forces that act upon any falling object. A parachute starts falling towards the ground due to the force of gravity but due to resistance of air caught in the open parachute the speed of the fall slowed down.

            During the descent of a parachute at a certain point when the air resistance and the pull of gravity are evenly balanced the parachute reaches a speed called terminal velocity. At this stage parachute descends at a constant speed.