Unit 6 - Key Words Energy Transfers and Sound 1

Question 1

a measure of the thermal energy in an object usually in degrees Celsius (oC)

Answer 1

temperature

Question 2

a unit of measurement on the temperature scale

Answer 2

degrees Celsius (oC)

Question 3

a unit of measurement on the temperature scale - 0 K is the coldest temperature that is thought to exist 0 K = -273 oC. A difference in temperature of 1 oC is also a difference in temperature of 1 K so 0 oC = 273 K and 100 oC = 373 K.

Answer 3

Kelvin (K)

Question 4

a form of (thermal) energy which flows from a hot to a cooler object

Answer 4

heat

Question 5

a unit of energy

Answer 5

joule (J)

Question 6

a diagram where arrows show how energy is transferred from one form to another

Answer 6

energy transfer diagram

Question 7

a diagram that shows the proportion of energy transferred to other forms – they are often used to represent the useful energy (straight on arrows) and wasted energy (arrows off to the side).

Answer 7

Sankey diagram

Question 8

a force that pulls masses towards one another

Answer 8

gravity

Question 9

stored energy that an object has because of its change in height

Answer 9

gravitational potential energy (J)

change in gravitational potential energy (J) = mass (kg) × acceleration due to gravity (N/kg) × change in height (m)

Question 10

energy that moving objects have

Answer 10

kinetic energy (J)

kinetic energy (J) = ½ × mass (kg) × velocity2 (m/s)2

Question 11

energy stored when an elastic object is stretched or compressed

Answer 11

elastic potential energy (J)

elastic potential energy (J) = ½ × force (N) × extension (m) – this is true as long as the object isn’t permanently stretched beyond its elastic limit.

Question 12

energy transferred by a force moving a load

Answer 12

work done (J)

work done (J) = force (N) × distance moved in the direction of the force (m)

Question 13

energy stored in bonds between atoms which becomes available if atoms are rearranged in a chemical reaction

Answer 13

chemical potential energy

Question 14

a gas in the air that is produced by plants, used during aerobic respiration and during combustion reactions

Answer 14

oxygen

Question 15

a reaction of fuels with oxygen that produces heat

Answer 15

combustion

Question 16

a compound containing only carbon and hydrogen e.g. fuels

Answer 16

hydrocarbon

Question 17

coal, natural gas and oil that were formed from the compressed remains of plants and other organisms that died millions of years ago

Answer 17

fossil fuel