Science Chapter 3 Study Guide

Science Chapter 3 Study Guide

Lesson 1:

Potential energy: stored energy m (an object can have potential energy due to its position defying gravity)

Kinetic energy: the energy of things in motion n nn nnnnnnnnnnnn(potential energy changes into kinetic energy) Example: A child at the top of a slide has nnnnnnnnnnnnpotential energy because she is defying gravity, as she starts to move down the slide the vvvvvvvvvvvvvvpotential energy changes to kinetic energy because she is now in motion.

Lesson 2:

Wave: a disturbance that carries energy from one point to another point

Wavelength: the distance between one crest and the next crest of a wave

Crest: the top of a wave

Trough: the bottom of a wave

Lesson 3:

Light energy: energy that we can see. vvvvvvvvvvvvLight travels outward from its source in ALL directions. (a light bulb) bbbbbbbbbbIt travels in straight lines until it strikes an object. bbbbbbbbbbLight is made up of different colors, which, when mixed is visible as WHITE light.

Absorb: when an object takes in some of the light that hits it. vvvvvvvvvvvvWhen ALL colors are absorbed an object looks BLACK. vvvvvvvvvvvvWhen none of the light is absorbed the object looks WHITE.

Reflect: when light BOUNCES OFF of an object. The color of the light that bounces off an object gives it vvvvvvvvvvvvvits color. Example: An apple is red because it absorbs all colors except red, which reflects, vvvvvvvvvvvvvor bounces off the apple.

Refract: when light BENDS or changes direction, as it passes through different materials at different dddddddddddspeeds. (straw in a glass of water that looks broken where the water meets the air)

Shadow: the dark area formed when an object BLOCKS light.

Lesson 4:

Sound energy: energy we can hear. Sound happens when an object vibrates. Sound travels in waves.

Volume: how loud of how softa sound is depending onhow much energythe sound has. vvvvvvvvvvvv(Turn up or turn down the volume on the radio!!!)

Pitch: how high or how low a sound is depending on the frequency of the vibrations. vvvvvvvvvvvvHigh frequency  vibrates quickly  HIGH PITCH

ccccccccccccccLow frequency  vibrates slowly  LOW PITCH

(Example: Guitar strings that vibrate quickly produce a high pitch. If they vibrate slowly, they produce a low pitch.)

Lesson 5:

Electric current: the movement or flow of electric charges from one place to another

Electric circuit: the PATH through which controlled electric current flows

Closed circuit: a circuit with no gaps or breaks

Open circuit: a circuit with a gap or break in the path.

Conductors: materials which allow electric charges to flow easily through them. vvvvvvvvvvvExamples of conductors: metals, especially copper, water, graphite

Insulators: materials which stop the flow of electric charges. ccccccccccccExamples of insulators: rubber, plastic, wood, glass.

People who work with electrical equipment wear rubber soled shoes and tools with rubber or plastic parts to protect them from electrical shocks. Metal wire used in electrical circuits arecovered in rubber or plastic because they are good insulators.