Lepton - Particles made up of two or three
quarks bound together by the strong force.
Linear Accelerator - An indivisible fundamental
particle. There are six leptons plus their antiparticles.
Laser - Device that produces coherent
light by stimulated emission of radiation.
Laser Induced Fusion - Proposed method of creating
nuclear fusion by using heating caused by intense laser beams to
squeeze matter together.
Law of Conservation of Energy - In a closed, isolated system, the
total momentum is constant.
Law of Reflection - Angle of incidence of a wave is
equal to the angle of reflection.
Law of Universal Gravitation - Gravitational force between two
objects depends directly on the product of their masses and
inversely on the square of their separation.
Lens - Optical device designed to
converge or diverge light.
Lens Equation - See mirror equation.
Lenz’s Law - Magnetic field generated by an
induced current opposes the change in field that caused the
Lever Arm - Component of the displacement of
the force from the axis of rotation in the axis of rotation in
the direction perpendicular to the force.
Light - Electromagnetic radiation with
wavelengths between 400 and 700 nm that is visible.
Linear Relationship - Relationship between two
variables, x and y, summarized by the equation y= ax + b, where
a and b are constant.
Linear Restoring Force - Force in direction toward
equilibrium position that depends linearly on distance from
distance from that position.
Liquid - Materials that have fixed volume
but whose shape depends on the container.
Lodestone - Naturally occurring magnetic
Longitudinal Waves - Wave in which direction of
disturbance is the same as the direction of travel of wave.
Loudness - Physiological measure of
amplitude of a sound wave; heard on pitch and tone color as well
Lumen - Unit of luminous flux.
Luminance Intensity - Measure of light emitted by
source in candelas; luminous flux divided by 4pie.
Luminous Flux - Flow of light from source
measured in lumens.
Luminous Object - Object that emits light, as
opposed to one that reflects light.
Lux - Unit of luminous flux; one lumen per square meter.