Physics - Energy

Question 1

Energy

Answer 1

Ability to do work
It can be stored

Question 2

Potential energy

Answer 2

Energy that is stored and when released is converted to other forms of energy
All substances and objects possess potential energy

Question 3

Gravitational potential energy

Answer 3

the energy that is stored by an object due to its height or position above the earth’s surface

Question 4

Elastic potential energy

Answer 4

the energy that is stored by an object that is stretched

Question 5

Chemical potential energy

Answer 5

the energy stored in chemical that when reacted together release heat, light or sound

Question 6

Nuclear potential energy

Answer 6

energy stored in the nucleus of atoms that can release energy slowly, such as in a nuclear reactor, or quickly, such as in a nuclear explosion

Question 7

Electrical potential energy

Answer 7

Energy that is carried by an electrical current (the movement of electrons, the negatively charged particles of atoms)

Question 8

Kinetic energy

Answer 8

energy possessed by objects that are moving

Question 8

Heat energy

Answer 8

energy that causes objects to get hotter

Question 9

Light energy

Answer 9

Energy that makes light visible to the human eye
It may be released when an object gets hot or when a chemical reaction occurs

Question 10

Mechanical energy definition and equation

Answer 10

The total energy an object has because of its motion (speed) and position
Potential energy + Kinetic energy

Question 11

Is all energy converted useful energy?

Answer 11

most energy is usually converted into useful energy but some is converted into forms of energy that are wasted or not so useful

Question 12

Law of Conservation of energy

Answer 12

energy can neither be created nor destroyed, only converted (changes forms)

Question 13

Energy Efficiency

Answer 13

the amount of energy that is utilised as useful energy versus wasted energy

Question 14

Why does higher temperature increase thermal (heat) energy?

Answer 14

this is as a higher temperature results to particles in an atom to move faster/quicker

Question 15

The 3 ways of heat transfer

Answer 15

Conduction
Convection
Radiation

Question 16

Conduction - Heat transfer

Answer 16

transfer of heat from the hotter end of a solid to the cooler end of a solid through the collision of neighbouring particles

Question 17

Why is conduction easier among solids and liquids?

Answer 17

this is as the particles are closer together already in liquids and solids so the particles only need to move a small distance in order to collide with each other and transfer heat

Question 18

Convection - Heat transfer

Answer 18

the movement of heat in liquids and gases usually through currents
A current is created when the warmer
(less dense) material rises forcing the
cooler (more dense) material to sink

Question 19

Radiation - Heat transfer

Answer 19

Heat from the sun reaches Earth by electromagnetic waves (radiation)

Question 20

Why is radiation different to conduction and convection?

Answer 20

unlike Conduction and Convection,
radiation can occur in empty space, as well as in solids, liquids, and gases

Question 21

Conductors

Answer 21

Good conductors of heat
They heat up quickly when exposed to a source of thermal energy

Question 22

Insulators

Answer 22

Poor conductors of heat
Insulators do not heat up
They keep cold things cold and hot things hot

Question 23

Why are Insulators useful?

Answer 23

Insulators are useful as they can be used to slow the change of temperature, which means that warm or hot substances will stay hotter longer, while cold substances will also stay colder for longer

Question 24

Heat transfer

Answer 24

the movement of heat from an object with a higher temperature to an object with a lower temperature