unit 3.5 Flashcards
(33 cards)
What are waves?
Waves are vibrations that transfer energy from place to place.
In transverse waves, how are the vibrations oriented in relation to the wave direction?
The vibrations are perpendicular (right angle) to the wave direction.
Name three examples of transverse waves.
- All waves on the EM spectrum
- Water waves
- Seismic S waves
In longitudinal waves, how are the vibrations oriented in relation to the wave direction?
The vibrations are parallel to the wave direction.
What are the two areas formed in longitudinal waves?
- Compression
- Rarefaction
Define compression in longitudinal waves.
An area of increased pressure where the waves are closer together than on average.
Define rarefaction in longitudinal waves.
An area of reduced pressure where the waves are further apart than on average.
What is amplitude?
The maximum height of the wave (or maximum disturbance from rest).
What is wavelength?
The distance between a point on one wave and the same point on the next wave.
What does frequency measure in waves?
The number of cycles of a wave that occur in one second, measured in Hz.
What is the Law of Reflection?
Angle of incidence = Angle of Reflection.
How are angles measured in the Law of Reflection?
Both angles (incidence and reflection) are measured from the normal.
What is the practical way to represent reflection?
Using a ripple tank.
What is refraction?
The change in direction of waves when they pass through the boundary between two different substances due to a change in density.
What happens to water waves when they move from deep water to shallow water?
They refract.
What occurs to light when it travels from air to glass?
Light travels slower in glass because it is more dense than air.
What remains constant when light travels from air to glass?
Frequency.
What happens to the wavelength of light when it travels from air to glass?
The wavelength decreases to ensure frequency doesn’t change.
Fill in the blank: The electromagnetic spectrum consists of ______ types of waves.
[seven]
What is a common characteristic of the seven waves in the electromagnetic spectrum?
They all travel at the speed of light and are all transverse waves.
As you go down the electromagnetic spectrum, what happens to wavelength, frequency, and energy?
- Wavelength decreases
- Frequency increases
- Energy increases
List the types of waves in the electromagnetic spectrum.
- Radio waves
- Microwaves
- Infrared
- Light / visible
- Ultraviolet
- X-rays
- Gamma Rays
What are the dangers of radio waves?
Very few.
What are some uses of microwaves?
- Heating body cells
- Satellite communication
- Cooking
- Phones
