Science - Chapter 8
friction
occurs when 2 surfaces rub together
absorption
occurs when a n object takes in a light wave - after a light wave is absorbed, it becomes a form of heat
oscilloscope
a device that takes sound waves and displays the shape of the waves on the screen - scientists study sound using these
sound wave
a disturbance that moves sound energy through matter - sound energy travels outward as sound waves
volume
a measure of how strong a sound seems to us - loudness
vibration
a quick back-and-forth movement
heat source
anything that gives off energy that particles of matter can take in
compressions
areas where particles bunch together
fossil fuels
coal, natural gas, and oil - sources of heat when burned
sound
energy in the form of vibrations passing through matter - sounds occur when objects vibrate - sound can travel through solids, liquids (quickly), and gases (more slowly) but cannot travel through empty space
electrical energy
energy caused by the movement of electrically charged particles - e.g. flip on a light switch
thermal energy
energy due to randomly moving particles that make up matter - felt as heat
kinetic energy
energy of motion - anything moving has this kind of energy - e.g moving swing or a hurricane - the amount depends on the speed and mass of the object
sound energy
energy of vibrations carried by air, water, or other matter - e.g. alarm clock or listening to music
radiation
energy sent out in waves - e.g. feel warmth from the sun or a fire
potential energy
energy that is stored in an object - when an object is in motion, its potential eery is released as other forms of energy - e.g. truck burning fuel - the potential energy in gas is released as sound, heat, and motion
forms of potential energy
gravitational, chemical, elastic
amplitude
height of a wave measured from its midline - the higher the amplitude, the more energy, the louder it sounds
pitch
how high or low a sound is -depends on the frequency of the sound wave - vibrate more quickly = higher pitch / vibrate more slowly = lower pitch
refraction
light changes speed when it passes into a new medium and bends - each color bends differently
reflection
light rays bounce off or reflect from a surface - smooth, shiny surfaces reflect more light rays than other objects
prism
piece of glass which separates white light into its different wavelengths
visible light spectrum
red, orange, yellow, green, blue and violet - always appear in the same order
sources of light
sun, bioluminescence (light from animals), fire
energy
the ability to cause motion or create change
wavelength
the distance between a point on the wave and a similar point on the next wave
visible light
the form of light energy we see - travels as waves - has wavelengths and frequencies
frequency
the number of waves that pass a point in a certain amount of time - the number of complete cycles a wave makes in one second
heat
the transfer of thermal energy between matter of different temperatures - thermal energy flows from something warm to something cool
conduction
transfer of heat that occurs when one thing touches another - e.g bird sitting on eggs, spoon sitting in oatmeal
convection
transfer of thermal energy as matter moves - gas or liquid moves from place to place
light energy
travels as waves and can move through empty space - some comes from the sun - e.g. sunflowers use light energy to make food
other forms of heat
when energy changes and gives off heat - e.g fossil fuels, light, laser light, sun/solar panel, friction
