exam time baby Flashcards
(46 cards)
high 2 low frequency
gamma (16-12), x ray(10), UV(8) ,light, infared(6-4), microwave 2), radiowaves tv longwave etc (1-8) all number to the power of 10
properties of electromagnetic waves
- waves originate from accelrating charges
- they transfer energy from one point to another
3.does no oscillate crets and troughs where field strongest
4.waves can travel through vaccum (3x10^8)
radio waves used for
fm radio or tv
microwaves used for
heating food and satellite comms
infared (below red) used for
nigth vision equipment
visible light
can detect with eyes made up of rainbow
ultraviolet
comes from sun
x rays used for
casting shadows on x ray film and scanning bags security
gamma rays
emitted during nuculear reactions can penetrate tissue
two types of waves
mech and electromagnetic
pulse
single disturbance in a medium.
1khz
1000 hz
1mhz
1,000,000 hz
v=fh and other nb is?
v= h divided by 1 divided by period
longitudal wave
a series of consecutive compressions and rarefractions move parallel to direction of propogation
particle movment of longitudal wave
vibrate backwards and forwards parral to prop
wave speed
speed at which compressions and rarefracrions move
speed of sound waves depends on
how closely packed togeter particles in the medium are (energy can transfer from one particle to the next)
how do we hear?
Sound Wave Reception: Sound waves travel through the air and reach the outer ear. These waves are essentially vibrations that carry energy.
Transmission in the Ear: The outer ear channels these vibrations into the ear canal, directing them toward the eardrum (a thin membrane). When the sound waves hit the eardrum, it vibrates.
Middle Ear Mechanics: The vibrations from the eardrum move a series of tiny bones in the middle ear called the ossicles (the malleus, incus, and stapes). These bones amplify and pass the vibrations to the inner ear.
Inner Ear Processing: The vibrations reach the cochlea, a spiral-shaped, fluid-filled structure. Inside the cochlea are thousands of tiny hair cells that move in response to the vibrations. This movement generates electrical signals.
Signal Transmission to the Brain: The auditory nerve picks up these signals and sends them to the brain.
Brain Interpretation: The brain processes and interprets these signals, allowing us to recognize sounds, such as speech, music, or environmental noise.
oscilloscope does
converts waves into trasverse wave patterns
higher frequency
higher pitch
high loud
high amplitude
at what frequencies can we not hear
20khz plus
ultrasound imaging
Sound Waves Sent: A small device called a transducer is placed on the skin. It sends sound waves at a frequency that’s too high for humans to hear.
Waves Echo Back: These sound waves travel into the body and bounce back when they hit something solid, like an organ or tissue.
Computer Processing: The returning echoes are picked up by the transducer, and a computer converts them into images on a screen. The speed and strength of the echoes help determine the shapes, sizes, and types of structures inside.
Image Display: The result is a live, moving image that shows what’s happening inside, making it helpful for observing things like blood flow or fetal development.
