Final Exam Review Flashcards
amplitude
The distance from the midpoint to the maximum (crest) of a wave, or equivalently from the midpoint to the minimum (trough).
beat
Periodic variation in the loudness of sound. Caused when two tones of slightly different frequencies are sounded together.
compression
A pulse of compressed air. Example: consider a long room with a door at one end and an open window with a curtain at the other end. When you open the door, the compressed air moves from the door to the curtain until the curtain flaps out the window. This is an example of compression.
constructive interference
Addition of two or more waves when wave crests overlap to produce a resulting wave of increased amplitude.
crest
One of the places in a wave where the wave is highest or the disturbance is greatest.
destructive interference
Combination of waves where crests of one wave overlap troughs of another, resulting in a wave of decreased amplitude.
Doppler Effect
The apparent change in the frequency of a wave due to the motions of the source or of the observer.
frequency (f)
The number of events (cycles, vibrations, oscillations, or any repeated event.) per time, measured in hertz (or events per time). Inverse of period.
Hertz (Hz)
The SI unit of frequency. One hertz (Hz) us one cycle per second.
interference pattern
A pattern formed by the overlapping of two or more waves that arrive in a region at the same time.
longitudinal wave
A wave in which the individual particles of a medium vibrate back and forth along (parallel to) the direction in which the wave travels–for example, sound.
natural frequency
A frequency at which an elastic object naturally tends to vibrate, so that minimum energy is required to produce a forced vibration or to continue vibration at that frequency.
pitch
How low or how high we perceive a sound to be. The higher the frequency, the higher the pitch. For example, a foghorn would have a low pitch, and a piccolo would have a high pitch.
rarefaction
A disturbance in air (or matter) in which the pressure is lowered. Example: consider a long room with a door at one end and an open window with a curtain covering it on the other. When the door is closed, it creates an area of low pressure which causes the curtain to blow inward.
resonance
To “resound” or sound again. Occurs when the frequency of forced vibrations on an object matches the object’s natural frequency, causing a dramatic increase in amplitude.
standing wave
a wave that appears to stand in one place, even though it is really two waves interfering as they pass through each other
transverse wave
A wave with vibration at right angles to the direction the wave is traveling. Light consists of transverse waves.
trough
One of the places in a wave where the wave is lowest.
wavelength
The distance between successive identical parts of the wave (crest to crest, trough to trough, etc.).
alternating current
electric current that rapidly reverses in direction
ammeter
a device that measures current
amperes (A)
SI unit of electric current
1 ampere = 1 coulomb per second
angle of incidence
the angle between an incident ray and the normal to the surface it encounters
angle of reflection
the angle between an reflected ray and the normal to the surface of reflection
angle of refraction
the angle between a refracted ray and the normal to the surface at which it is refracted
capacitance (C)
the ability of an object to store electric charge
capacitor
a device used to store charge in a circuit
centi- (c)
one-hundredth
10-2
charging by conduction
transferring electric charge between objects by simple touching
charging by friction
transferring electric charge between objects by rubbing
charging by induction
redistributing electric charges in and on objects by the electrical influence of a charged object close by but not in contact
circuit
any complete path along which electric charge can flow
concave mirror
a mirror that curves inward like a “cave”
conductor
(a) a material in which heat can be transferred
(b) a material through which electric charge can flow (usually a metal)
converging lens
a lens that is thicker in the middle than at the edges and refracts parallel rays of light passing through it to a focus
convex mirror
a mirror that curves outward
the virtual image formed is smaller and closer to the mirror than the object
coulomb (C)
SI unit of electric charge
Coulomb’s Law
relationship among electrical force, charges, and distance
critical angle
the smallest angle of incidence for which a light ray is totally reflected within a medium
current (I)
the flow of electric charge that transports energy from one place to another
measured in amperes (amps for short)
direct current
electric current in which the flow of charge is always in one direction
diverging lens
a lens that is thinner in the middle than at the edges, causing parallel rays of light passing through it to diverge as if from a point
echo
a reflection of sound
electric charge (C)
a fundamental electric property to which the mutual attractions or repulsions between electrons or protons is attributed
electric field
a force field that fills the space around every electric charge or group of charges
measured by force per charge (Newtons/Coulomb)
electric potential energy
the energy that a charge has due to its location in an electric field
electric power (P)
the rate of electric energy transfer or the rate of doing work
power = current × voltage
electromagnetic spectrum
the range of electromagnetic waves extending from radio waves to gamma rays (low to high frequency)
RMI V UXG
electromagnetic wave
an energy-carrying wave emitted by vibrating charges (often electrons)
composed of oscillating electric and magnetic fields that regenerate one another