Physics Definitions for Gcse Level

Topics: Nuclear power, Earth, Energy Pages: 2 (770 words) Published: February 14, 2012
Double Award Physics Definitions Hookes Law Hookes law states that the extension of a spring is directly proportional to the load applied provided the elastic limit is not exceeded. Elastic Limit The elastic limit is the point beyond which the spring will not return to its original shape when the load is removed Centre of Mass The point through which all of an objects mass appears to act. Centre of gravity The point through which all of an objects weight appears to act Principle of Moments If an object is balanced then the sum of the clockwise moments will equal the sum of the anticlockwise moments about the same pivot. Transverse Wave The vibrations of the particles are perpendicular to the direction of energy flow Longitudinal Wave The vibrations of the particles are parallel to the direction of energy flow Amplitude The maximum displacement of a particle from its rest position Wavelength The distance between two neighbouring peaks or two neighbouring troughs Frequency The number of waves that pass a point in one second

Time Period The time for a particle to complete one full vibration or the time for one wave to pass a point. Luminous An object which emits its own light Non Luminous An object which does not emit its own light. It reflects light Dispersion White light contains seven colours. Each colour travels at a different speed in glass and so refracts by a different amount. Red refracts the least and violet refracts the most. This gives a spectrum of white light Principle of Conservation of Energy Energy cannot be created or destroyed; it can only be changed from one form into another. Renewable Energy Sources Energy resources which can be replaced in less than one human lifetime (70 yrs) Non-Renewable Energy Sources Energy resources which are used up quicker than they can be replaced. Or Energy resources which take longer than a human lifetime to replace Fossil Fuels Made from the remains of dead plants and animals which have decayed and been...