Module 11 Flashcards
What is a wave?
A disturbance that propagates (moves) in a medium
What is amplitude (A)?
The height of a wave.
What is wavelength (lamda)?
The distance between the crests (or troughs) of waves.
What is frequency (f)?
The number of waves that hit a certain point every second.
What is a transverse wave?
A wave whose propagation (movement) is perpendicular to its oscillation.
What is a longitudinal wave?
A wave whose propagation (movement) is parallel to its oscillation.
What is compression?
The crests of a longitudinal wave.
What are refractions?
The troughs of a longitudinal wave.
What is pitch?
An indication on how high or low a sound is, which is primarily determined by the frequency of the sound wave.
What is volume?
An indication of how loud a sound is, which is determined primarily by the amplitude of the sound wave.
Are sound waves longitudinal or transverse?
Longitudinal.
What is the Doppler effect?
The change in pitch caused by relative motion between the source of the sound and the observer of the sound.
What are sonic waves?
Sound waves with a frequency between 20 and 20,000 Hz. These are sound waves people can hear.
What are ultrasonic waves?
Sound waves with a frequency greater than 20,000 Hz. People can’t hear these.
What are infrasonic waves?
Sound waves with a frequency under 20 Hz. People can’t hear these.
What is the speed of light in air (to 2 significant figures)?
3.0 x 10^8 m/sec
What does the speed of light depend on?
The speed of light changes depending on the medium through which they travel. Generally speaking, as the medium gets more dense, light waves slow down.
What is diffraction?
The spreading of waves around an obstacle.
What is a coherent light wave?
Light waves in which the spatial relationship of the crests and troughs of one wave compared to the other does not change.
What is wave interference?
The phenomenon that occurs when 2 or more waves overlap their crests and troughs mix to make a different wave.
What is constructive interference?
The phenomenon that occurs when 2 or more waves overlap so that their crests and troughs add together to make larger crests and troughs.
What is destructive interference?
The phenomenon that occurs when 2 or more waves overlap so that their crests and troughs cancel one another out.
What is photoelectric effect?
The term that refers to the fact that when light is shone on certain metals, electrons can be liberated from the metal.
What are photoelectrons?
Electrons liberated from a metal via the photoelectric effect.
What is work function?
The energy that an electron in a metal must have in order to break free of the metal.
What is partical-wave duality?
The idea that anything in nature has both wave-like characteristics and particle-like characteristics.
What is Plancks constant?
6.63 x 10^-34
