Energy

Question 1

Law of Conservation of Energy

Answer 1

a law that states that energy cannot be made or lost. However, energy can be transformed from one type to another or transferred from one object to another.

Question 2

gravitational potential energy

Answer 2

energy stored due to the height of an object above a base level

Question 3

chemical energy

Answer 3

potential energy derived from chemical reactions

Question 4

elastic potential energy

Answer 4

the potential energy stored in a stretched elastic material

Question 5

nuclear energy

Answer 5

the energy stored at the center of atoms, the tiny particles that make up all substances. Nuclear energy can be released from the radioactive metals uranium or plutonium, and transformed into electrical energy in a nuclear power station.

Question 6

efficiency

Answer 6

the fraction of energy supplied to a device as useful energy. It is usually expressed as a percentage.

Question 7

conduction

Answer 7

the process by which heat or electricity is directly transmitted through the material of a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

Question 8

convection

Answer 8

the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.

Question 9

radiation

Answer 9

the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization.

Question 10

conductors

Answer 10

a person who directs the performance of an orchestra or choir.

Question 11

insulators

Answer 11

a substance which does not readily allow the passage of heat or sound.

Question 12

density

Answer 12

the degree of compactness of a substance

Question 13

radiant heat

Answer 13

heat transferred by radiation, as from the sun to the Earth

Question 14

reflected

Answer 14

bounced off

Question 15

transmitted

Answer 15

passed through something, such as light or sound passing through air

Question 16

absorbed

Answer 16

taken in

Question 17

deciduous

Answer 17

describes plants that lose their leaves during autumn and winter

Question 18

luminous

Answer 18

releasing its own light

Question 19

incandescent

Answer 19

describes objects that emit light when they are hot

Question 20

bio luminescent

Answer 20

describes living things that release light energy

Question 21

non-luminous

Answer 21

describes objects that do not emit their own light, but can be seen by reflected light

Question 22

scattered

Answer 22

describes light sent in many directions by small particles within a substance

Question 23

vibrations

Answer 23

repeated fast, back-and-forth movements

Question 24

compression

Answer 24

the process of pushing a material into itself

Question 25

rarefaction

Answer 25

in sound waves, the layers of air particles that are spread apart (between compression)

Question 26

sound waves

Answer 26

vibrations of particles in the air

Question 27

frequency

Answer 27

number of vibrations in one second, or the number of wavelengths passing in one second

Question 28

hertz

Answer 28

unit of frequency; its abbreviation is Hz. One hertz is equal to one vibration every second.

Question 29

pitch

Answer 29

the highness or lowness of a sound. The pitch that you hear depends on the frequency of the vibrating air.

Question 30

wavelength

Answer 30

distance between two neighboring crests or troughs of a wave. This is the distance between two particles vibrating in step.

Question 31

amplitude

Answer 31

maximum distance that a particle moves away from its undisturbed position

Question 32

reverberation

Answer 32

longer-lasting sound caused by repeated reflection from hard surfaces