# Physics OCR AS Key Terms

Key terms and definitions for OCR Physics AS

- Created by: Rhianna Ward
- Created on: 01-12-10 11:49

First 304 words of the document:

PHYSICS AS KEY TERMS

Absorption line spectrum A dark line of a unique wavelength seen in a continuous spectrum

Acceleration The rate of change of an object's velocity. Unit = ms-2

Ampere the unit of electric current (A)

Amplitude The maximum displacement of a particle from its equilibrium position

Antinode A point on a stationary wave with maximum amplitude

Average speed the total distance travelled by an object divided by the total time taken

Braking distance the distance travelled by a vehicle from the moment when the brakes are

applied until the vehicle comes to rest

Brittle describes a material that shows no plastic deformation and breaks just beyond its elastic

limit

Centre of gravity the point where the entire weight of an object appears to act

Charge carrier any charged particles, such as electrons, responsible for a current

Coherent two sources are coherent when they emit waves with a constant phase difference

Components (of a vector) the magnitudes of a vector quantity in two perpendicular directions

Compression a region in a sound wave where the air pressure is greater than its mean value

Compressive a force that squeezes an object

Constructive interference when two wave have no half wavelength phase difference, construct to

give increased amplitude, maxima

Coulomb the unit of electrical charge. A charge of 1C passes a point when a current of 1A flows for

1s. 1C = 1As

Density the mass per unit volume of a material.

Destructive interference when two waves cancel to give reduced amplitude

Diffraction the spreading of a wave when it passes through a gap or past the edge of an object

Dispersion the splitting of light into its different wavelengths

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