waves Flashcards
teach
What is Wavelength (λ)?
Distance between two crests or troughs, measured in meters.
What is Amplitude?
Height of the wave from the rest position; determines wave energy.
What are Crest and Trough?
The highest and lowest points of a wave.
What is Frequency (f)?
Number of wave cycles per second, measured in Hertz (Hz).
How does frequency relate to energy?
Higher frequency = higher energy, lower frequency = lower energy.
What are Mechanical Waves?
Waves that require a medium (air, water, solid) to travel.
What are examples of Mechanical Waves?
Sound waves, water waves, seismic waves.
What are Electromagnetic Waves?
Waves that do not require a medium; can travel through space.
What are examples of Electromagnetic Waves?
Radio waves, microwaves, infrared, visible light, UV, X-rays, gamma rays.
What is Reflection?
A wave bounces off a surface at the same angle it arrived (e.g., echo, mirror reflection).
What is Refraction?
A wave changes speed and direction when entering a new medium (e.g., light bending in water).
What is Resonance?
When an object vibrates at its natural frequency due to an external wave, amplifying its motion (e.g., breaking a glass with sound).
What is Scattering?
Waves spread out after hitting particles (e.g., blue sky due to light scattering).
What is the Doppler Effect?
Frequency changes when the wave source moves relative to the observer (e.g., ambulance siren pitch shift).
What is the Electromagnetic Spectrum?
The EM spectrum includes all types of electromagnetic waves, arranged by wavelength and frequency.
What are Radio Waves?
Long wavelength, low frequency, low energy waves used in communication (radio, TV, Wi-Fi).
What are Microwaves?
Used in cooking and mobile phones.
What is Infrared (IR)?
Heat radiation, night vision.
What is Visible Light?
The only part of the spectrum that human eyes can see (400-700 nm).
What are the colors of Visible Light?
Red, Orange, Yellow, Green, Blue, Indigo, Violet.
What is Ultraviolet (UV)?
Causes sunburn, used in sterilization.
What are X-rays?
Used in medical imaging.
What are Gamma Rays?
Highest energy, used in cancer treatment.
What is a Continuous Spectrum?
All wavelengths of visible light, like sunlight.
What is an Absorption Spectrum?
A continuous spectrum with missing wavelengths (dark lines).
Formed when light passes through a gas, and certain wavelengths are absorbed; used to identify elements in stars.
What is an Emission Spectrum?
Bright lines on a dark background, showing specific wavelengths emitted by an element when electrons fall to lower energy levels.
What are examples of Wireless Communication?
Wi-Fi, Bluetooth, Mobile Phones.
What is a Base Station?
A communication tower that connects mobile phones to a network.
What is the Binary System?
Digital data is stored as 1s and 0s (on and off signals).
What is Modulation?
A method to encode digital signals on a carrier wave.
What is Amplitude Modulation (AM)?
Changes wave height.
What is Frequency Modulation (FM)?
Changes wave frequency.
What are the types of Radioactive Decay?
Alpha (α), Beta (β), Gamma (γ).
What is Alpha decay?
Heavy, slow, stopped by paper.
What is Beta decay?
Lighter, penetrates skin, stopped by aluminum.
What is Gamma decay?
High energy, deeply penetrating, stopped by lead.
What are uses of Radiation?
Cancer treatment, sterilization of medical equipment, radiocarbon dating.
What are the effects of Ionizing Radiation?
Can damage DNA, leading to mutations; high exposure increases cancer risk.
What is the Big Bang?
The universe began ~13.8 billion years ago from an extremely hot and dense state.
What is Redshift?
Light from distant galaxies is stretched, showing the universe is expanding.
What is Cosmic Background Radiation?
Leftover heat from the early universe, detected as microwave radiation.
What is Element Abundance?
The universe has mostly hydrogen and helium, as predicted.
