waves Flashcards
when you refer to sound waves what do you usually talk about?
volume and pitch, the higher the frequency, the higher the pitch
what is anything above 20kHz called?
ultrasound
what is time period?
the time it takes to produce one wave
what is the method for the ripple tank practical?
- set up a ripple tank like in the diagram with around 5cm of water
- adjust the height pf the wooden rod so it just touches the water’s surface
- switch the lamp and the motor on until low frequency waves can be clearly observed
- measure length of a number of waves then divide by the number of waves to calculate wavelength, practical to take a photo for measurements
- count number of waves passing a point in 10 seconds then divide by ten for frequency
- calculate wave speed using frequency x wavelength
name the method of of frequency of a wave on a string (practical)
- attach a string to the vibration generator and use 200 gram hanging mass and pulley to pull the string taut, place the wooden bridge under the string near the pulley
- switch on vibration generator and adjust bridge until stationary unit waves can be clearly observed
- measure length of as many half wavelengths as possible, divide by number of wavelengths. this is half doubling, it gives the wavelengths
- frequency is the frequency of power supply
- calculate sped by wave speed = frequency x wavelength
what is inside a transverse wave?
peak, amplitude, wavelength, trough
what is inside a longitudinal wave?
compressions, rarefactions, wavelength, amplitude
what is the name given to reflected sound waves
echo
what order is the electromagnetic spectrum?
radio, microwave, infrared, visible, ultraviolet, x-ray, gamma
what are some uses of radio waves?
broadcast radio and tv
what are some uses of microwaves?
cooking, radar, phones, other signals
what are some uses of infrared waves?
radiators, heat detector
what are some uses of visible light?
makes things able to be seen
what are some uses of ultraviolet?
sun tanning, energy efficient lamps
what are some uses of x rays?
medical screening
what are some uses of gamma?
sterilise hospital equipment
what are some hazards of radio waves?
no known dangers
what are some hazards of microwaves?
possible heat damage
what are some hazards of infrared
skin burns
what are some hazards of visible light?
bright light can cause eye damage
what are some hazards of uv
eye damage, sunburn, skin cancer
what are some hazards of x-rays
kills cells, mutations, cancer
what are some hazards of gamma
cancer, mutations, kill cells
