Wave Properties and Behavior
Waves transfer energy without transferring matter. Key wave properties include amplitude (maximum displacement), wavelength (distance between equivalent points), frequency (waves per second, in hertz), and period (time for one complete wave). The wave speed equals frequency × wavelength.
Waves can be transverse (oscillations perpendicular to direction of travel, like light) or longitudinal (oscillations parallel to direction of travel, like sound). When waves meet boundaries, they can undergo reflection, where the angle of incidence equals the angle of reflection. Rough surfaces cause diffuse reflection (scattering), while smooth surfaces produce specular reflection mirror−like.
An object's color depends on which wavelengths it absorbs or reflects. An object appears black if it absorbs all wavelengths, and white if it reflects all wavelengths. Colour filters work by absorbing certain wavelengths and transmitting others.
Sound science: The human ear can detect sound waves between 20Hz and 20kHz, but some animals can hear ultrasound waves above 20kHz. We use these for medical imaging and detecting objects underwater through echo sounding!
The Earth's structure can be studied using seismic waves produced by earthquakes. P-waves (primary) are longitudinal and can travel through solids and liquids, while S-waves (secondary) are transverse and cannot travel through liquids, helping scientists identify the Earth's liquid outer core.