Science: Chapter 4
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Science: Chapter 4
What type of energy is transported by a wave?
A wave does not carry matter, it carries___________.
What are transverse waves?
In a transverse wave, the movement of the vibrations is up and down.
What is a longitudinal wave?
In a longitudinal wave, the movement of the vibrations is forward and backward.
What are the two types of waves?
Mechanical and Electromagnetic.
What are mechanical waves?
Mechanical waves are waves that need a medium in order to propagate.
What are electromagnetic waves?
Electromagnetic waves are waves that do not need a medium to propagate.
Fill in the blanks with transverse or longitudinal.
A) Light is a ________ wave.
B) Sound is a ________ wave.
Sound needs a __________ to travel.
Light does not need a _________ to travel.
What is the decibel scale?
The decibel scale is a scale that measures the intensity of sound as perceived by the human ear.
Wavelength is measured in ___________ or _________?
Metres or Centimetres.
High frequency sound waves make _____ pitch
Low frequency sound waves make ________ pitch sounds.
What is the average range of human hearing?
20 Hz to 20 000 Hz
What is a frequency below 20 Hz called?
What is a frequency above 20 000 Hz called?
What is refraction?
Refraction is the bending of light as it passes from one transparent medium to another.
What is a lens?
A lens is a transparent object that has at least one curved surface and that can refract light as it passes.
What are the two types of lens'?
Converging and Diverging.
What is the amplitude of a wave?
The amplitude is the distance from the equilibrium point to the top of the crest or trough.
What is a wave?
A wave is a disturbance that travels through a medium or the vacuum of space.
What is wavelength?
Wavelength is the length of the wave, from crest to crest, trough to trough or from equilibrium point to equilibrium point.
What is frequency?
Frequency is the number of cycles per unit time.
What is frequency measured in? What's its symbol.
Hertz and Hz.
What does cycle correspond to?
Cycle corresponds to the length of one compression and one rarefaction.
What is the electromagnetic spectrum?
The electromagnetic spectrum organises all electromagnetic waves according to their wavelength and their frequency.
What are the 6 waves that are on the electromagnetic spectrum, in order from long wavelength to short wavelength?
1. Radio Waves
3. Visible Light
4. Ultraviolet Rays
6. Gamma Rays
What is an example of a technological application for radio waves?
What is an example of a technological application for infrared?
-Night Vision Goggles
-Space Observation Satellites
What is an example of a technological application for visible light?
What is an example of a technological application for ultraviolet rays?
-Treatment of certain ailments
-Sterilization of surgical instruments
What is an example of a technological application for X-Rays?
-Baggage inspection at airports
What is an example of a technological application for gamma rays?
Visible light separates into different colours, what are these colours?
Red, Orange, Yellow, Green, Blue and Violet.
What is light?
Light is an electromagnetic wave that is visible to the human eye.
What is reflection?
Reflection is the rebounding of light that occurs when a light ray comes into to contact with a different medium, then bounces back to its original medium.
What is the incident ray?
The incident ray is the ray that contacts the surface of an object.
What is the reflected ray?
The reflected ray is the ray that rebounds.
The angle of incidence is always __________________________.
Equal to the angle of reflection.
What are the two types of reflection?
Diffuse and Specular.
What is a diffuse reflection?
Parallel light waves are reflected from an irregular surface in all directions and there is no image formation.
What are the three characteristics of a reflected image in a plane mirror?
The image is:
-The same size as the object