waves

• the particles that make up a wave oscillate about a fixed point, in doing so they pass the energy onto the next particles
• the eneregy moves on but the matter remains
• frequency- number of waves passing a fixed point per second
• amplitude- maximum displacement of any particle from its undisturbed position
• wavelength- distance from one point of a wave to the equivalent next point
• period- time taken for for one complete oscillation
• electromagnetic waves are transverse waves
• transverse is the up and down one
• when a wave passes from one medium to another it can be refracted and change direction
• the direction of a refracted wave depends on- the angle at which the wave hits the boundary and the materials invloved
• electromagnetic spectrum- radio waves, micro waves, infrared radiation, visible light, ultraviolet light, x-rays, gamma rays.
• ultraviolet, x-rays and gamma rays hold enough energy to have hazardous effects on the human body- skin cancer