energy

Question 1

What is a system?

Answer 1

• an object or a group of objects.

Question 2

What energy change occurs when an object is projected upwards?

Answer 2

• Kinetic energy is transferred to gravitational potential energy.

Question 3

What energy changes occur when a moving object hits an obstacle?

Answer 3

• Kinetic energy is transferred to sound, heat, and deformation (internal energy).

Question 4

What energy change happens when an object is accelerated by a constant force?

Answer 4

-object gains kinetic energy.

Question 5

What energy change happens when a vehicle slows down?

Answer 5

-Kinetic energy is transferred to thermal energy (due to friction and braking).

Question 6

What energy change happens when water is boiled in an electric kettle?

Answer 6

-Electrical energy is transferred to thermal energy (heating the water).

Question 7

What are the units for each part of the kinetic energy equation?

Answer 7

Ek: Joules (J)

m:Kilograms (kg)

V: Metres per second (m/s)

Question 8

how is each symbol in the elastic potential energy formula measured?

Answer 8

Ee: Elastic potential energy (Joules)
k: Spring constant (N/m)
e: Extension (metres)

Question 9

When is the elastic potential energy equation valid?

Answer 9

-When the spring has not exceeded its limit of proportionality.

Question 10

how is gravitational potential energy measured?

Answer 10

in joules

Question 11

how is mass measured?

Answer 11

-in kg

Question 12

how is gravitational field strength measured?

Answer 12

-in n/kg

Question 13

how is height measured?

Answer 13

-in m

Question 14

how is change in thermal energy measured?

Answer 14

-in joules

Question 15

how is specific heat capacity measured?

Answer 15

in j/kg°C

Question 16

What is specific heat capacity?

Answer 16

-The energy needed to raise the temperature of 1 kg of a substance by 1°C.

Question 17

how is power measured?

Answer 17

-in watts

Question 18

how is work done measured?

Answer 18

-in joules

Question 19

What is 1 watt equal to?

Answer 19

• 1 joule of energy transferred per second.

Question 20

Can energy be created or destroyed?

Answer 20

-No. Energy can only be transferred, stored, or dissipated.

Question 21

What does thermal conductivity tell us?

Answer 21

-How quickly energy is transferred through a material by conduction.

Question 22

What are the main energy resources on Earth?

Answer 22

-Fossil fuels (coal, oil, gas)
-Nuclear fuel
-Bio-fuel
-Wind
-Hydro-electric
-Geothermal
-Tides
-The Sun
-Water waves

Question 23

What is a renewable energy resource?

Answer 23

• One that is replenished naturally as it is used.

Question 24

What are common uses of energy resources?

Answer 24

-Transport, electricity generation, and heating.

Question 25

name 8 energy stores

Answer 25

-thermal -gravitational potential -elastic potential -magnetic -chemical -electrostatic -nuclear -kinetic

Question 26

give four ways energy can be transferred

Answer 26

-mechanically -electrically -through heating via infrared radiation -via light or sound waves

Question 27

what do we mean by magnetic energy store?

Answer 27

-the energy stored when repelling magnetic poles are pushed closer together, or when attracting magnetic poles are pulled further apart

Question 28

what do we mean by thermal energy store?

Answer 28

-it refers to how much energy a substance has, it includes two stores of energy: -the kinetic energy store -the potential energy store

Question 29

what do we mean by chemical energy store?

Answer 29

-the energy stored in chemical bonds such as those between atoms

Question 30

what do we mean by kinetic energy store?

Answer 30

-the energy an object possesses due to its motion

Question 31

what do we mean by gravitational potential energy store?

Answer 31

-the energy an object has due to its height in a gravitational field strength

Question 32

why do we mean by electrostatic energy store?

Answer 32

-the energy stores when repelling charges have been moved closer together or when attracting charges have been pulled further apart

Question 33

what do we mean by elastic potential energy store?

Answer 33

-the energy stored when an object is stretched or squashed

Question 34

what do we mean by nuclear energy store?

Answer 34

-the energy stored in the nucleus of an atom

Question 35

as an object falls which energy store does energy pass between?

Answer 35

-the energy will pass from its gravitational potential energy store to its kinetic energy store

Question 36

what is kinetic energy?

Answer 36

-the energy that it possesses due to its motion

Question 37

which two measurements are required to calculate the kinetic energy of an object?

Answer 37

-the mass and velocity of the object

Question 38

how is velocity measured?

Answer 38

-in metres per second (m/s)