The noise that the plane makes is sometimes so loud that you cannot hear any other noise. Sound is a type of energy. Sounds are produced when an object vibrates. When this happens, the air around the object also vibrates. These vibrations in the air travel as sound waves. A jet engine makes a great deal of sound energy. The engine sounds loud when it is close, but you can sometimes hear the noise when the plane is even several miles away from you.
Definition of Polymer. A large molecule consisting of chains or rings of linked monomer units, usually characterized by high melting and boiling points.
What are Polymers? Polymers are substances containing a large number of structural units joined by the same type of linkage. These substances often form into a chain-like structure. Polymers in the natural world have been around since the beginning of time. Starch, cellulose, and rubber all possess polymeric properties. Man-made polymers have been studied since 1832.