Waves Flashcards
What is the primary function of waves?
Waves transfer energy.
What are the two classifications of waves?
Longitudinal waves
Transverse waves
How do particles in longitudinal waves move?
Particles vibrate back and forth parallel to the energy transfer.
How do particles in transverse waves move?
Particles move side to side, perpendicular to the energy transfer, while energy is transferred at 90 degrees.
What are examples of longitudinal waves?
Sound and ultrasound.
What is included in the electromagnetic spectrum?
Light waves.
What is the definition of amplitude in a wave?
Amplitude is the maximum displacement of a particle from its rest position.
What does the wavelength of a wave represent?
Wavelength is the distance from one point on a wave to the equivalent point on the adjacent wave.
How is frequency measured?
Frequency is measured in Hertz (Hz).
What happens to waves when they encounter a material?
Waves can be reflected, absorbed, or transmitted through the material.
What is the normal line in the context of wave reflection?
The normal line is a line drawn at 90 degrees to the surface where the wave is reflected.
What is the approximate speed of sound in air at ground level?
About 330 meters per second.
How do sound waves travel through air?
Sound waves travel through vibrations of particles that compress and rarefy the air.
What is the frequency range that humans can hear?
From 20 Hz to 20,000 Hz (20 kHz).
What are seismic waves?
Seismic waves are waves generated by earthquakes or massive underground movements.
What are the two types of seismic waves?
- Primary waves (P-waves): Longitudinal, can travel through liquids and solids.
- Secondary waves (S-waves): Transverse, cannot travel through liquids.
How do P-waves and S-waves differ in their ability to travel through materials?
P-waves can travel through both liquids and solids, while S-waves can only travel through solids.
What is the speed of light in a vacuum?
300,000 kilometers per second.
What are the seven main categories of the electromagnetic spectrum?
mnemonic: Rabbits Mate In Very Unique eXpensive Gardens
- Rabbits = Radio waves
- Mate = Microwaves
- In = Infrared
- Very = Visible light
- Unique = Ultraviolet
- eXpensive = X-rays
- Gardens = Gamma rays
How does the wavelength change across the electromagnetic spectrum?
Wavelength decreases from radio waves to gamma rays.
What types of waves do we detect during an earthquake?
Primary and secondary waves
What does the detection of primary and secondary waves tell us?
It informs us about the structure of the Earth beneath us
What happens to the wavelength and frequency as you move from radio waves to gamma rays?
The wavelength decreases and the frequency increases
Why are higher frequency electromagnetic waves considered more dangerous?
They are more ionizing
How are microwaves used in communication?
They are used in mobile phones and satellite communication
What is infrared radiation used for?
Heating and night-vision technology
What is visible light used for?
Fiber-optic communication
What are some applications of ultraviolet light?
Energy-efficient lamps and sun tanning
What is refraction?
It is the change in direction of a wave when it meets a different medium
What happens to light when it passes through a glass block?
It changes direction due to a change in speed
What are the two main types of lenses?
Convex and concave lenses
How does a convex lens affect light?
It brings light rays together at a point
How does a concave lens affect light?
It spreads light rays apart
What type of image does a concave lens produce?
A smaller virtual image
How does colour relate to the visible spectrum?
Each color has its own frequency and wavelength
What happens when green light passes through a green filter?
All of the green light gets through
What happens when green light hits a red filter?
No light gets through
Why does a red object appear red?
It reflects red light and absorbs other colors
How does the Earth’s energy balance relate to global warming?
If the Earth absorbs more energy than it emits, its temperature rises
What role do greenhouse gases play in the Earth’s temperature?
They make it harder for energy to escape, contributing to temperature rise
What are the uses of different parts of the electromagnetic spectrum?
Radio: Television and radio communication
Microwaves: Mobile phones and satellite communication
Infrared: Heating and night-vision technology
Visible light: Fiber-optic communication
Ultraviolet: Energy-efficient lamps and sun tanning
X-rays: Medical imaging and treatment
Gamma rays: Medical treatment
What is the process of refraction?
- A wave meets a different medium.
- The wave changes speed and direction.
- The wave front hits the surface at different times.
- One side slows down before the other, causing a change in direction.
How do colors interact with filters?
A green filter allows green light to pass through.
A red filter allows red light to pass through.
Combining filters can block all light if no common color is present.
what are the three rules for refraction in a convex lens?
1) an incident ray parallel to the axis refracts through the lens and passes through the principal focus on the other side
2) an incident ray passing through the principal focus refracts through the lens and travels parallel to the axis
3) an incident ray passing through the centre of the lens carries on in the same direction
what are the three rules for refraction in a concave lens?
1) an incident ray parallel to the axis refracts through the lens, and travels in line with the principal focus (so it appears to have come from the principal focus)
2) an incident ray passing through the lens towards the principal focus refracts through the lens and travels parallel to the axis
3) an incident ray passing through the centre of the lens carries on in the same direction
what two ways can waves be reflected?
- diffuse reflection: when a wave is reflected by a rough surface and the reflected rays are scattered in lots of different directions
- specular reflection: when a wave is reflected in a single direction by a smooth surface.
