Chapter 17 Study Guide Flashcards
(25 cards)
What is wave bending as it moves through a new material at an angle?
Wave bending occurs due to slowing down in a new medium
Example: broken straw in a glass, ‘guy in a pool’
What is wave bending when it hits an obstacle or passes through a gap?
Wave bending occurs as diffraction
Example: Mr C talking through the gap in the door, water hitting a sandcastle
What is amplitude?
Amplitude is how high or low a wave goes above or below the resting line
It is related to the wave’s amount of energy
What is periodic motion?
A motion that repeats itself in a specific amount of time
Example: weekly paycheck
What is frequency and what are its units?
Frequency is the number of waves occurring during a given time, measured in Hertz (Hz)
What is wavelength and what are its units?
Wavelength is the distance of a single wave, measured in meters
How is wavelength measured for a transverse wave?
Wavelength is measured from crest to crest or trough to trough
How is wavelength measured for a longitudinal wave?
Wavelength is measured from compression to compression or rarefaction to rarefaction
What happens to the wavelength if the frequency of a wave is increased?
The wavelength decreases
Frequency and wavelength are inverses: High frequency = short wavelength, Low frequency = long wavelength
What formula relates speed, wavelength, and frequency of waves?
v = wavelength x frequency
What is reflection in wave behavior?
Reflection is when a wave bounces off of things it cannot pass through
Results in the wave inverting or going upside down
What is refraction?
Refraction is the bending of waves as they pass through different media
Example: Light bending in water
What is diffraction?
Diffraction is the bending of waves around obstacles or through openings
What are waves that move so fast that they become imperceptible?
These waves form a vibrating or pulsating motion
Occurs when waves and their reflections move very fast
What is constructive interference?
When two identical waves occupy the same space, their amplitudes add together
Resulting amplitude looks larger than individual waves
What is destructive interference?
When two opposite waves occupy the same space, their amplitudes subtract from each other
Resulting amplitude looks smaller or non-existent
What describes sound waves?
Sound waves are longitudinal waves that travel from a sound source to a receiver
What are the five properties of sound waves?
- Frequency
- Wavelength
- Amplitude
- Speed
- Intensity
What is wave intensity and what units are used to measure it?
Wave intensity is a measure of how much sound waves you are receiving, measured in Decibels (dB)
How does loudness differ from intensity?
Intensity describes the waves, while loudness describes how that intensity feels to your ears
How are frequency and pitch related?
Frequency describes the waves, while pitch describes how that intensity feels to your ears
What can ultrasound be used for?
- Imaging a baby in the womb
- SONAR for underwater navigation
- Dog whistles
What is the Doppler effect?
The change in pitch (frequency) of a sound if the source is moving
Higher pitch if moving toward you, lower pitch if moving away
What are mechanical waves? How are they created? (ANT CONFIRM)
Mechanical waves are disturbances that travel through a medium (like air, water, or a solid) and transfer energy. They are created when a force acts on a medium, causing it to vibrate and then transferring that vibration to neighboring particles.
