P6 Homework - Retrieval Practice Flashcards
What are the 2 different types of wave?
Longitudinal (e.g. sound)
Transverse (e.g. light)
Give an example of a transverse wave?
Light
All electromagnetic waves e.g. radio / mircowaves / infra-red / visible light / Ultra-Violet / Gamma
Give an example of a longitudinal wave?
Sound
Describe
a) a transverse wave
b) a longitudinal wave
a) Transverse wave - Movement is perpendicular (at right angles) to energy
b) Movement is parallel to energy
Describe 3 differences between light and sound waves
- Light is transverse
- Sound is longitudinal
- Light travels at 300000000m/s
- Sound travels at 330m/s (in air)
- Light can travel through a vacuum
- Sound cannot travel through a vacuum
Define these terms
Amplitude
Wavelength
Frequency
Amplitude - Maximum displacement of the wave (e.g. from the middle to the peak)
Wavelength - Distance from peak to peak (or trough to trough)
Frequency - Number of waves per second
What are these measured in?
Amplitude
Wavelength
Frequency
Amplitude - Metres (m)
Wavelength - Metres (m)
Frequency - Hertz (Hz)
What are the uses of Radio Waves?
Communication
Short waves used for radio and TV
Longer waves can be send radio signals around the world
What are the uses of Microwaves?
Communication - Microwaves are used to communicate with satellites
Cooking - Microwaves heat the water in the food
What are the uses of Infrared?
Heating - Electric heaters release a lot of Infrared radiation to heat a room
Infrared cameras - create a picture using heat. The hotter the object the more infrared given out
What are the uses of Visible light?
Sending data - Optical fibres carry data a long way. The information is sent as light rays that bounce along the fibre
What are the uses of Ultraviolet waves?
Energy Efficient Lights
Security pens (ink glows under UV light)
Sunbeds
What are the uses of X-Rays?
Checking for broken bones
Treating cancer
What are the uses of Gamma Rays?
Treating cancer
Sterilising medical equipment
Medical tracers
Which electromagnetic waves are used in medical treatment?
X-Rays - Broken bones / Cancer treatment
Gamma Rays - Cancer treatment / Sterilising equipment
What is the Leslie cube experiment designed to investigate?
How different surfaces affect the amount of Infrared radiation emitted (given out)
What can you use to investigate how the surface of an object affects the infrared radiation emitted?
Use a Leslie cube (Cube with different surfaces e.g. black, white, shiny, matt)
Fill with hot water
Record the temperature (of infrared) emitted from each side
In the Leslie cube experiment, what is the
a) Independent Variable
b) Dependent Variable
c) Control Variable
a) Type of surface
b) Infrared/temperature given off
c) Distance from the cube of the infrared detector/thermometer
What are the 4 sides of the Leslie cube like?
Black Matt paint
White Matt paint
Shiny Metal
Dull Metal
How does the type of surface affect the Infrared radiation emitted?
Black surfaces emit more infrared radiation than white
Matt surfaces emit more infrared radiation than shiny
What is the equation for calculating wave speed?
Wave speed (m/s) = Frequency (Hz) x wavelength (m)
Which electromagnetic waves are harmful?
Ultraviolet - can cause skin cancer
X-rays - can cause cancer
Gamma rays - can cause cancer
Why are some electromagnetic waves harmful?
UV/X-ray/Gamma
Can cause genes to mutate leading to cancer
What equipment can be used to measure calculate the speed of a wave?
The ripple tank
Shallow tray of water
Vibrations create waves
Waves cast shadows on a screen under the tank
How can the ripple tank be used to calculate the speed of a wave?
- Vibrations create waves
- Waves cast shadows on a screen under the tank
- Measure the distance of 10 ways. Divide by 10 to get 1 wavelength
- Count time taken for 10 waves. Divide by 10 to get frequency of waves each second
- Use Speed = Frequency x wavelength to calculate speed
In the ripple tank experiment, why is it better to measure 10 waves and divide by 10?
Larger measurement is more accurate
In the ripple tank experiment, how can you measure wavelength?
Take a picture and measure the distance of 10 waves. Then divide by 10
In the ripple tank experiment, how can you measure frequency?
Count how many waves pass in 10 seconds. Then divide by 10
In the ripple tank experiment, how can you increase the accuracy of your measurements?
Measure 10 waves and divide by 10
What is the order of the electromagnetic spectrum?
How can you remember this?
Radio / Microwaves / Infrared / Visible light / Ultraviolet / X-rays / Gamma
Remember / My / Instructions / Visible / Under / Xray / Glasses
Which electromagnetic waves have the longest wavelength?
Radio waves
