4.1.1 Energy Changes In A System And The Ways Energy Is Stored Before And After Such Changes

Question 1

What is a system?

Answer 1

A system is an object or a group of objects

Question 2

What is the equation for kinetic energy?

Answer 2

0.5xmass x velocity squared

Question 3

What is kinetic energy measured in ?

Answer 3

Joules ( J )

Question 4

What is mass measured in?

Answer 4

Kilograms (kg)

Question 5

What is velocity measured in?

Answer 5

Metres per second (m/s)

Question 6

What is the equation for elastic potential energy?

Answer 6

0.5 x spring constant x extension squared

Question 7

What is elastic potential energy measured in?

Answer 7

Joules ( J )

Question 8

What is spring constant measured in?

Answer 8

Newtons per metre ( N/m )

Question 9

What is extension measured in ?

Answer 9

Metres ( m )

Question 10

What is the equation for gravitational potential energy?

Answer 10

Mass x gravitational field strength x height

Question 11

What is gravitational potential energy measured in?

Answer 11

Joules ( J )

Question 12

What is gravitational field strength measured in?

Answer 12

Newtons per kilogram ( N/kg )

Question 13

What is height measured in?

Answer 13

Metres ( m )

Question 14

What is the equation for specific heat capacity?

Answer 14

Change in thermal energy = mass x specific heat capacity x change in temperature

Question 15

What is change in thermal energy measured in ?

Answer 15

Joules ( J )

Question 16

What is specific heat capacity measured in ?

Answer 16

Joules per kilogram per degrees Celsius ( J/kg degrees celsius

Question 17

What is temperature change measured in?

Answer 17

Degrees celsius

Question 18

What is specific heat capacity?

Answer 18

The amount of energy required to raise the temperature of one kilogram of the substance by one degrees Celsius

Question 19

What is elastic potential energy?

Answer 19

The energy stored in an elastic object when work is done in the object

Question 20

What is kinetic energy?

Answer 20

The energy stored in a moving object when work is done on the object

Question 21

What is gravitational potential energy.

Answer 21

The energy stored in an object that is above the ground when work is done

Question 22

What is power?

Answer 22

The rate at which energy is transferred or the rate at which work is done

Question 23

What is the equation for power?

Answer 23

Energy transferred / time

Question 24

What does work equal?

Answer 24

Energy transferred

Question 25

What is power measured in?

Answer 25

Watts ( W )

Question 26

What is work / energy transferred measured in ?

Answer 26

Joules ( J )

Question 27

What is an energy transfer of 1 joule per second equal to?

Answer 27

A power of 1 watt

Question 28

What is the conservation of energy?

Answer 28

Energy can be transferred usually stored or dissipated but cannot created or destroyed

Question 29

What is the term wasted energy used for ?

Answer 29

Energy that isn’t used usefully

Question 30

What does the higher the thermal conductivity equal?

Answer 30

The higher the thermal conductivity of a material the higher the rate of energy transfer by conduction across the material

Question 31

What is the equation of efficiency?

Answer 31

Useful output energy transfer/ total input energy transfer

Question 32

What is another equation for efficiency?

Answer 32

Useful power output / total power input

Question 33

What are the main energy resources available for use on earth?

Answer 33

Fossil fuel , nuclear fuel , bio fuel , wind , hydroelectricity, geothermal, the tides , the sun and water waves

Question 34

What is a renewable energy source ?

Answer 34

A source that is being or can be replenished as it is used

Question 35

What are some uses of energy resources?

Answer 35

Transport, electricity generation and heating

Question 36

What is spring constant?

Answer 36

a measure of the stiffness of the spring