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