Notes on Sound and Light Properties

Ljudvåg: A wave consisting of regions of thinner (low pressure) and denser (high pressure) air.
Vakuum: Airless space where no molecules exist to push against one another; sound cannot travel in space due to this vacuum.

Frekvens: Number of oscillations per second measured in Hertz (Hz). Higher frequency results in a higher-pitched sound.
Ultraljud: Sound waves exceeding a frequency of 20,000 Hz, commonly used in medicine to examine fetuses.
Infraljud: Sound waves with a frequency lower than 20 Hz.
Eko: Sound that returns after bouncing off surfaces such as walls or cliffs.
Ekolod: A device that measures distance using sound waves, utilized in submarines.
Decibel (dB): Unit measuring sound intensity or loudness.

Reflektera: The phenomenon where light bounces off surfaces. Objects are visible because they reflect light from sources (e.g., a lamp) into our eyes.
Normalen: An imaginary line perpendicular to a surface, such as a mirror.
Reflektionslagen: The law of reflection states that the angle of incidence equals the angle of reflection.

Brytning: The bending of light due to a change in its speed when transitioning from a less dense medium (e.g., air) to a denser medium (e.g., water or glass). Light bends towards the normal.

Parallella ljusstrålar: Light rays that remain parallel and never converge.
Konvex lins: A lens that converges incoming rays where the focal point lies beyond the lens.
Konkav lins: A lens that diverges incoming rays, reducing the size of the reflected image.
Konkav spegel: A mirror that converges light rays to a point, used in car headlights to create parallel beams.
Konvex spegel: A mirror that diverges light rays, minimizing the image size, often found in vehicle side mirrors.

Light exhibits characteristics of both waves and particles, traveling at a speed of 300,000 km/s in a vacuum.
Våglängd: The distance between two wave peaks; blue light has the shortest wavelength.
Foton: The smallest unit of light.
Laser: A specific type of electromagnetic wave with precise frequency and phase requirements.