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82 terms

Lachman's Final

Everything from the study guide.
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speed
distance an object travels per unit of time
average speed
calculated by dividing the total distance by the total time of travel
displacement
distance & direction of an object's position from the origin
velocity
includes speed and direction of motion
acceleration
occurs when an object changes its speed, direction, or both
inertia
the tendency of an object to resist change in motion
force
push or pull that one body exerts onto another
balanced forces
forces on a body that are equal in size and opposite in direction
instantaneous speed
speed at any given time
friction
force that opposes motion between two touching surfaces
weight
the gravitational force exerted on an object
momentum
the product of the mass of an object and its velocity
static friction
exists between two surfaces that are not moving past each other
gravity
when two masses exert an attractive force on each other
chemical potential
energy stored in the chemical bonds between atoms
gravitation potential
depends on the mass of the object, its height above the ground, and its acceleration due to gravity
joule
SI unit of energy
kinetic
energy in the form of motion
mechanical energy
the sum of the potential and kinetic energy in a system
elastic potential
energy stored by something that can stretch or compress
heat
produced by the flow of electrons through a material
insulator
material that does NOT allow electrons to easily flow through it
resistance
tendency of a material to oppose the flow of electrons through it
parallel circuit
type of circuit that mas more than one branch for current to flow
power
equals current X voltage difference
voltage
the "push" that cause charge to move in a circuit
series circuit
circuit with only one path for current to flow
transformer
can be used to increase or decrease the voltage in alternating current (AC)
electrical generator
converts mechanical energy into electrical energy
turbine
a large wheel that rotates when pushed by water, wind, or steam
poles
region where the magnetic forces of a magnet is strongest
direct current
batteries produce this type of electron flow
galvanometer
device that uses and electromagnet to measure electric current
electromagnetic induction
a generator works based on the principle
alternating current
reverses the direction of current flow in a regular way
electromagnet
made of a soft iron core surrounded by loops of current-carrying wire
fossil fuel
includes coal, petroleum, and natural gas
photovoltaic cell
converts light energy into electricity
petroleum
crude oil that is highly flammable former by decaying organisms
nonrenewable
energy source that cannot be replaced as fast as it used
biomass
includes organic matter such a wood and rice hulls
nuclear waste
radioactive by-product resulting from the use of radioactive sources
geothermal
thermal energy form the earth that can be used to generate electricity
hydroelectric
electrical energy produced from the energy of moving water
constructive interference
when two or more waves overlap and combine to form a new wave
diffraction
the bending of a wave as it changes speed when passing from one medium to another
wavelength
measured from crest to crest or trough to trough in a transverse wave
medium
matter that a wave travels through
transverse
matter moves back and forth at right angles to the direction the wave travels
compressional
an example of this type of wave is sound
frequency
the number of wavelengths that pass a given point each second
rarefraction
the less dense region of a compressional wave
amplitude
relates directly to the energy carried by a wave
sonar
uses reflected underwater sound waves to detect objects
dB (decibels)
units used to measure the intensity of sound
doppler effect
change of pitch or wave frequency due to a moving wave source
acoustics
the study of sound
ultrasonic
sound waves above the normal frequency range of human hearing
cochlea
part of the ear that converts sound waves into nerve impulses
resonator
hollow chamber filled with air that amplifies vibrating sound waves
visable
portion of the electromagnetic spectrum that you can see
infared
type of energy used to produce thermograms
ultraviolet
the ozone layer above the earth blocks much of this radiation
photon
particle whose energy is dependent on the frequency of the light
x-ray
often used in medicine to produce images of the body
electromagnetic spectrum
is composed of vibrating electrical and magnetic fields
gamma
very high energy, short wavelength wave that can damage cells
radio
short waves often used in communications
coherent light
light of only one wavelength that travels with its crest and troughs aligned
translucent
allows some light to pass through, but you cannot see clearly through it
infared
is produced when objects become so hot that that give off light
opaque
does not allow any light to pass through
pigment
colored material that absorbs some colors and reflects others
concave or diverging
lens that is thinner in the middle than at the edges
mirror
smooth, flat surface that reflects an image
focal length
distance from the center of lens or mirror to the point of focus
cornea
transparent outer covering of the eye
real image
image formed when light rays converge
optical axis
imaginary line drawn perpendicular to the surface of a mirror or lens at its center
retina
part of the eye that converts light images into electrical signals
convex or converging
lens that is thicker in the middle than on the edges
convex mirror
reflects an image that is virtual,upright, and smaller than the object