From west to east the six standard time zones in Europe are: (UTC/GMT -1) Azores Time Zone. (UTC/GMT +0) Greenwich Mean Time Zone, Western European Time Zone and Irish Time Zone. (UTC/GMT +1) Central European Time Zone.
Mechanical waves transport energy. This energy propagates in the same direction as the wave. Any kind of wave (mechanical or electromagnetic) has a certain energy. Mechanical waves can be produced only in media which possess elasticity and inertia. A mechanical wave requires an initial energy input. Once this initial energy is added, the wave travels through the medium until all its energy is transferred. In contrast, electromagnetic waves require no medium, but can still travel through one.
Earth is the medium for earthquake waves. Waves that can travel only through a medium are called mechanical waves. Most waves, including water waves, sound waves, and earthquake waves, are mechanical waves. Electromagnetic waves are the most common kind of nonmechanical waves. READING TOOLBOX Compare After you read this section, make a chart comparing transverse and longitudinal waves.