Energy

Question 1

What is a system?

Answer 1

An object or group of objects.

Question 2

What is kinetic energy?

Answer 2

The energy stored in moving objects.

Question 3

What objects do not have kinetic energy?

Answer 3

Stationary objects.

Question 4

What is elastic potential energy?

Answer 4

Elastic potential energy is the energy stored in an object when it is stretched or compressed, like a spring

Question 5

What is meant be extensions in terms of springs?

Answer 5

The distance of the stretch made by the force applied on the spring.

Question 6

What happens when we apply to greater force on a spring?

Answer 6

The extension is no longer directly proportional to the force as the spring is stretched beyond the limit of proportionality.

Question 7

What is the outcome for the spring after it has stretched beyond its limit of proportionality?

Answer 7

It will no return back to its original length.

Question 8

What is the gravitational protentional energy?

Answer 8

The energy stored in a object due to its position above the earth surface.

Question 9

Why type of force is acting on the object during gravitational protentional energy?

Answer 9

Gravity.

Question 10

What is specific heat capacity?

Answer 10

Specific heat capacity is the amount of energy needed to raise the temperature of 1 kg of a substance by 1°C.

Question 11

What does “Δ” mean?

Answer 11

Change in

Question 12

What is thermal energy?

Answer 12

The energy stored in an object due to an object temperature.

Question 13

What is the law conservation of energy?

Answer 13

Energy cannot be created or destroyed, only transferred, stored, or dissipated.

Question 14

What is a closed system?

Answer 14

Where energy can not enter or leave.

Question 15

What does friction cause energy to do?

Answer 15

Cause energy to be transferred to thermal energy.

Question 16

Where is friction in a pendulum?

Answer 16

The pendulum passing through the air particles.

Question 17

What does it mean when energy is dissipated?

Answer 17

Wasted

Question 18

Why do Pendulum stop moving at some point?

Answer 18

The friction from the air to the pendulum is dissipated and cause it to swing with less energy eventually stopping it.

Question 19

How can we reduce unwanted energy transfer?

Answer 19

Reduce friction: -use lubricant on fix point
-remove air particles around the pendulum
-use of thermal insulation

Question 20

What is work done?

Answer 20

whenever energy is transferred from one store to another.

Question 21

What does mechanical work involve?

Answer 21

Involves a force to move an object.

Question 22

What does electrical work involve?

Answer 22

Involves a current transferring energy.

Question 23

What is power?

Answer 23

Power is how quickly (the rate) energy is transferred or work is done.

Question 24

What is the unit for power?

Answer 24

1 Watt (W)

Question 25

1 Watt is an energy transfer of..?

Answer 25

1 watt is an energy transfer of 1J per second.

Question 26

What is efficiency?

Answer 26

Efficiency is the fraction of the input energy that is usefully transferred.

Question 27

How does thermal conductivity affect the rate of energy transfer by conduction?

Answer 27

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

Question 28

What are example of things in our house with a low thermal conductivity?

Answer 28

Cavity between walls: insulating material with low thermal conductivity

Question 29

How can we reduce thermal energy transfer in a house?

Answer 29

-Construct the building with low thermal conductivity -thick walls

Question 30

What are the 3 main uses of energy?

Answer 30

Transport Generating electricity Heating

Question 31

What are the 3 main fossil fuels?

Answer 31

coal oil gas

Question 32

What are the advantages of fossil fuels?

Answer 32

-Reliable (always provide energy when needed) -Releases great deal of energy -abundant and cheap -versatile

Question 33

What are disadvantages of fossil fuels?

Answer 33

-release huge amount of co2 -non-renewable -can release other pollutants

Question 34

Is nuclear power renewable?

Answer 34

nah its lwk non-renewable

Question 35

What do nuclear power plants run on?

Answer 35

Run on the elements: -uranium -plutonium

Question 36

What is advantages of nuclear power?

Answer 36

-nuclear power plants release no co2 -extremely reliable

Question 37

What is disadvantages of nuclear power?

Answer 37

-contain highly dangerous radioactive material -decommissioning of power plants take years and cost a lot. -generates large amounts of highly dangerous radioactive waste

Question 38

What is the UK abundant in?

Answer 38

Reserves of coal.

Question 39

Why was switching from coal to gas in the UK good?

Answer 39

-burning gas generates less co2 then coal -short start-up times

Question 40

What are examples of usefull energy resources?

Answer 40

-Tidal power -Wave power -geothermal power -hydroelectric power -biofuel