Science Cycle Test T4 Flashcards
Define Wave:
A transfer of energy (disturbance) that spreads through a medium from the disturbance location, usually as vibrations in the medium.
Define Medium:
The material or substance through which the wave travels.
Define Transverse Wave:
Wave that consists of a disturbance occurring perpendicular (at right angles) to the travel direction of the wave
Define Longitudinal wave:
Wave that consists of a disturbance occurring parallel to the travel direction of the wave.
Define a Pulse Wave:
Wave that is caused by a single disturbance.
Define a Periodic Wave:
Wave that is caused by a continuous and repetitive disturbance.
Define Amplitude:
For any given position in the medium, the maximum displacement of the medium from its starting position.
Define Wavelength:
At any given (frozen moment of) time, the distance over which the wave’s shape repeats.
Define Period (Physics):
For any given position in the medium, the duration of a single vibration (oscillation).
Define Frequency:
For any given position in the medium, the number of vibrations per second.
Define Sound:
Longitudinal wave travelling through a medium which can be detected by the ear.
Define Pitch:
The frequency of the sound wave.
Define Electromagnetic waves:
A wave consisting of a vibrating electric field which causes a vibrating magnetic field.
Define Light:
Electromagnetic waves that can be detected by the eye.
Define Luminous object:
An object that gives off light.
Define Diffuse reflection:
The reflection of light from a surface such that a ray incident on the surface is scattered.
Define Specular reflection:
The reflection of light from a surface such that a ray incident on the surface is reflected at the same angle; mirror-like reflection.
Define Refraction:
The change in direction of a wave passing from one medium to another one, where it travels at a different speed.
Describe all electro-magnetic radiations speed whilst passing through a vacuum.
All electromagnetic radiation travels at the same speed in a vacuums.
If a water wave in the ocean has a frequency of 1.25Hz. It’s time period is:
0.8 seconds.
X-rays work because the bones…:
Absorb the radiation and are therefore visible.
List the 7 types of waves:
1) Radio Waves
2) Microwaves
3) Infrared
4) Visible light
5) Ultraviolet
6) X-ray
7) Gamma rays
What type of wave can be split into different colours?
Visible light.
What type of wave has the longest wavelenght?
Radio-waves.
Which type of wave has the lowest frequency?
Radio-waves.
Which type of wave is the most ionising?
Gamma rays.
Describe the process of Ultrasound detecting nearby objects?
- Ultrasound waves are emitted from the transmitter through the medium to the object.
- When the waves reach the fish they are reflected back.
- The reflected waves are detected by the receiver.
- The time for the wave to reach the object and reflect back is used to calculate the objects distance (divide by 2)
How would you find the distance?
speed x time
How would you find the speed?
distance ÷ time
How would you find the time?
distance ÷ speed
How would you find the velocity (speed)?
wavelength x frequency.
Give an example of how we use visible light for communication.
Fiber Optic Cables
Electromagnetic waves have all got the same ____.
Speed.
What is the speed of electromagnetic waves passing through a vacuum?
300 000 kilometres per second.
How do you find the wavelength?
speed ÷ frequency.
How do you find the frequency?
speed ÷ wavelength
If the speed of a wave stays the same but it’s wave stays the same buts its wavelength decreases, then the frequency of the wave will:
Increase.
If Middle C has a frequency of 256Hz and Middle A has a frequency of 440Hz describe the wavelengths of both notes, which one is longer/shorter?
The wavelength of Middle C will be longer because the higher the frequency the shorter the wavelength and Middle A has a higher frequency and therefore a longer wavelength than Middle C.
Which of the following waves has the lowest frequency?
A. an AM radio wave of wavelength 600 m.
B. an FM radio wave of wavelength 8.7 m.
C. a microwave of wavelength 5 mm.
D. a radar wave of wavelength 9 cm.
A :D
What is the first rule of reflection?
Theta I (angle or incidence) = Theta R (angle of reflection)
What is the second rule of reflection?
The incident ray, refracted ray and the normal (to the surface) all lie on the same plane.
The amount of information that can be transmitted by a communication channel is called it’s ______.
Bandwidth.
Define Electro Magnetic waves:
Transverse electric and magnetic fields positioned at right angle to each other and travelling through empty space at the speed of light.
Define Optical Fibre.
A narrow tube of glass or plastic used to transmit pulses of light.
Define X-rays.
High energy electromagnetic radiation that can penetrate materials.
Transverse electric and magnetic fields positioned at right angle to each other and travelling through empty space at the speed of light.
Electromagnetic waves.
A narrow tube of glass or plastic used to transmit pulses of light.
Optical Fibre.
High energy electromagnetic radiation that can penetrate materials.
X-rays.
Out of the 7 types of waves which ones are ionising?
1) Ultraviolet rays.
2) X-ray rays
3) Gamma rays
Define high energy electromagnetic radiation:
Waves that can travel in a vacuum with a frequency higher than that of visible light.
Explain how X-rays can harm living tissue.
The ionising properties of X-rays mean that they can damage the DNA in cells or even kill cells.
Name the type of wave that has a wavelength of 30 cm?
Radio waves:
Why can radio waves be used for communication?
- Save
- Fast
- Easy to produce
- Travel everywhere at the same time
Name the physical phenomenon that allows light to be trapped in the optical fibre.
- Total internal reflection.
Name the process used on ships/submarines to detect nearby objects?
Sonar/Ultrasound.
If an alarm is put in a bell jar and air is gradually sucked out describe what would happen.
Gradually the sound would soften because sound cannot travel through vacuum mediums due to the lack of particles.
What are the parts of the Transverse wave? (5)
1) Trough
2) Crest
3) Wavelength
4) Amplitude
5) Node
What are the parts of the longitudinal wave? (3)
1) Compression
2) Refraction
3) Wavelength
What are waves the transfer of?
Energy.
What is a period?
How long it takes to complete one full wave cycle. (measured in seconds)
Frequency and a Period are _______ to eachother?
Inversely proportional - behave opposite in nature.
What symbol is a Period identified as?
T.
If the frequency of a wave doubles then the period will ______.
Halve.
What unit do you always want your wavelength in?
Metres.
Give 2 examples of longitudinal waves.
- Shock waves
- Sound
The seven types of waves can be described in to ways both _____ and _____ waves, what are they.
1) Transverse
2) Electromagnetic
Does changing the frequency of the wave change the speed?
No.
If the medium stays the same then the speed of the wave will?
Not change/remain constant.
The speed of a wave is CONSTANT in any given medium. T/F?
True ;)
If a wave has high frequency its wavelength is _____.
Short(er)
If a wave has low frequency its wavelength is _____.
Wide(r)
How fast is the speed of light in a vacuum?
3 x 10⁸ m/s
List the 7 types of waves and give one example of what they do.
1) Radio waves - broadcasting communication
2) Microwaves - cooking food
3) Infrared - Heater
4) Visible light - communication
5) Ultraviolet - fluorescent lights
6) X-rays - medical scanning
7) Gamma rays - chemotherapy.
At what stage is a frequency considered to be Ultrasound?
Over 200, 000 waves per second.
Which way do the electric field waves move?
Up and Down.
Which way do the magnetic field waves move?
Side to side.
Light is a form of _____.
Energy.
Light travels in straight lines called ___.
Rays.
Reflection also known as:
Specular reflection.
Define diffuse reflection.
The refraction of light from a surface such that a ray incident on the surface is scattered.
Define Refraction.
When a wave travels between mediums it bends away of towards the perpendicular depending on the densities between mediums.
Frequency of sound =
pitch.
What is the speed of sound in air?
340 m/s
If the ray passes from more dense to less dense it bends ______ the normal
Away from.
Define Biconcave:
Rounded on both sides.
If the ray passes from less dense to more dense it bends ______ the normal
Towards.
What acronym can be used to remember the types of waves.
Giant Xylophones Usually Live In Music Rooms.
Sound needs a medium to be heard explain what would happen if you tried to omit sound through a vacuum.
A vacuum is the absence of a medium so sound cannot pass through and would not be heard.
The speed of sound varies according to the medium. T/F?
True ;)
What factors might affect the speed of sound travelling?
The temperature and material of the medium.
Sound travels faster at lower temperatures. T/F?
False ;)
The greater the amplitude the ____ the
particles are moving because they have
more _____.
Faster.
Energy.
What types of waves are used for communication?
Microwaves, radio waves, visible light, ultrasound.
What frequencies are audible to human ears?
Sound waves with a frequency between 20 Hz and 20 KHz.
Sounds lower than 20Hz are called?
Infrasound.
Sounds higher than 20kHz are called?
Ultrasound.
List three uses of ultrasound:
- Breaking down kidney stones.
- Scanning unborn babies
- Cleaning delicate instruments and jewellery
Give 2 advantages and 2 disadvantages of ultrasound.
Advantages:
- Non-Invasive
- Real time imaging
Disadvantages:
- Poorer resolution the further down you go.
- Relies on expertise of sonographer
What is an echo?
A reflection of sound.
The speed of a wave is dependent on the ______.
Medium.
If the medium doesn’t change, then the speed
of the wave is _______.
Constant.
What does an oscilloscope do?
An oscilloscope converts sound waves into
electrical signals that can be viewed on a
screen.
Sound travels at a speed of about ____ m/s in seawater.
1500
