# Physics- P1.5

HideShow resource information

P1.5&6

Waves

• Waves have energy.
• Particles on the surface of the wave go up and down.
• Waves transfer energy.

Mechanical Waves

• Vibrations that travel through a medium (substance)
• Examples:
• Sound waves
• Water waves
• Waves on springs/ ropes
• Seismic waves from earthquakes

Electromagnetic Waves

• These waves travel through a vacuum atb the sane speed.
• Examples:
• Light waves
• Microwaves

Longitudianal Waves- The direction of the vibration or oscillation is parallel to the direction of energy transfer (the direction in which the wave travels) e.g. sound.

Transverse Waves- The direction of vibration or oscillation of is perpendicular to the direction of energy transfer (direction in which the wave travels) e.g. water.

Wave Characteristics

• Wavelength- Top of one peak to the other- bottom of trough to another.
• Amplitude- Distance from baseline to peak or baseline to trough.
• Frequency- N.o of waves per second if one wave passes in one second it has a frequency of one Hertz or Hz. This is the unit for frequency.

LIGHT TRAVELS IN STRAIGHT LINES

Image in a plane mirror

• Upright
• Same size as the object
• Distance from mirroe to image= distance from images to mirror
• Laterally inverted (flipped around)
• Virtual- can't be shown on a screen. (The image is called virtual because the light rays never really go there- our brains just think the do).

Diffraction

• Diffraction is the bending of waves round an obstacle or through a hole. The spreading out of waves.
• Maximum diffraction occurs when the wavelength is similar to the gap size.

Refraction

• Refraction of light in the bending of light rays at the interface…