energy

Question 1

List all the forms of energy

Answer 1

Magnetic, Kinetic, Heat, Light,Gravitational Potential, Chemical, Sound, Electrical, Elastic, Nuclear

(MostKidsHateLearningGCSEEnergyNames)

Question 2

What is the law of conservation of energy?

Answer 2

Energy cannot be created or destroyed. It can be transferred form one form to another

Question 3

What is magnetic energy?

Answer 3

Energy in magnets and electromagnets

Question 4

What is kinetic energy?

Answer 4

The energy in moving objects

Question 5

What is gravitational potential energy?

Answer 5

Energy stored in raises objects, the higher the object the higher the GPE

Question 6

What is chemical energy?

Answer 6

Energy in fuel, foods and batteries

Question 7

What is sound energy?

Answer 7

Energy released by vibrating objects

Question 8

What is electrical energy?

Answer 8

Energy in moving charges or static electric charges

Question 9

What is elastic (potential energy)?

Answer 9

Stored energy in stretched or squashed objects

Question 10

What is nuclear energy?

Answer 10

Stored energy in the nuclei of atoms.

Question 11

What is energy measured in?

Answer 11

Joules (J)

Question 12

What is the formula for kinetic energy?

Answer 12

KE = mv²
——
2

m: mass (kg)
KE: kinetic energy (J)
v: velocity (m/s)

Question 13

How would you work out the mass using the kinetic energy equation?

Answer 13

m = 2 x KE
———
v²

m: mass (kg)
KE: kinetic energy (J)
v: velocity (m/s)

Question 14

How would you work out the velocity using the kinetic energy equation?

Answer 14

v² = 2 x KE
——— ———> √v
m

m: mass (kg)
KE: kinetic energy (J)
v: velocity (m/s)

Question 15

What is the formula for gravitational potential energy?

Answer 15

GPE = m x g x h

GPE: gravitational potential energy (J)

m: mass (kg)
g: gravitational field strength (N/kg)
h: height (m)

Question 16

What is the equation for efficiency?

Answer 16

efficiency = useful energy output
——————————
energy input

The higher the efficiency , the more efficient it is

Question 17

What is conduction?

Answer 17

A method in which heat can be transferred between objects

Question 18

How does conduction happen?

Answer 18

Particles are heated and they gain both heat energy and kinetic energy. The particles collide with others, sharing heat energy this continues along the whole solid until all the particles are vibrating quickly.

Question 19

What is the test for conduction?

Answer 19

The ball and the hoop

Question 20

Why does conduction only happen in solids?

Answer 20

In solids the particles are closer together as compared to liquids and gases and this means energy is transferred more effectively

Question 21

What is convection?

Answer 21

Heat transfer that occurs in fluids (liquids and gases)

Question 22

How does convection work?

Answer 22

When heat is added to the particles they rise and become less dense compared to the cooler ones. This is called the convection current.

Question 23

What is thermal radiation?

Answer 23

Thermal radiation presents the amount of heat energy given off. Larger, hotter objects emit more than smaller cooler ones

Question 24

What are the colours used in thermal radiation to represent heat energy?

Answer 24

❤ RED: hot (highest energy ❤
💚YELLOW/GREEN: (less hot than red) 💚
💙BLUE: cooler than yellow/green💙
💜PURPLE: coldest💜

Question 25

What significance is the colour black to thermal radiation?

Answer 25

The darker the colour, the better absorber of thermal radiation. Black is also the best emitter of thermal radiation

Question 26

How do surfaces work with thermal radiation?

Answer 26

The matte-er the surface, the better absorber/emitter. Silver surfaces are worse absorbers and emitters of thermal radiation however they are the best reflectors of thermal radiation.

Question 27

What is a vacuum flask?

Answer 27

Designed to prevent RADIATION EVAPORATION CONVECTION AND CONDUCTION.

Question 28

What is the function of a plastic cap in the vacuum flask?

Answer 28

poor conductor so it reduces energy transfer by convection and conduction. it also prevents evaporation as water cannot escape.

Question 29

Why is the vacuum flask double walled?

Answer 29

it is a poor conductor so it prevents conduction

Question 30

Why are the inside surfaces silver?

Answer 30

because silver reflects infrared radiation

Question 31

Why is it a vacuum?

Answer 31

it prevents energy transfer via conduction and convection

Question 32

What is meant by a closed system?

Answer 32

energy is neither going in or out.

Question 33

What happens to wasted energy?

Answer 33

it spreads out into the surroundings and nothing can be done because energy cannot be created nor destroyed.