Topic 3 ⚖️💥

Question 1

In a closed conservation system with no energy transfers in or out, the total energy is?

Answer 1

Constant

Question 2

What is the law of conservation?

Answer 2

Energy cannot be created or destroyed, only transferred from one form to another

Question 3

What does higher thermal conductivity mean?

Answer 3

Greater rate of energy transfer

Question 4

How is insulation helpful?

Answer 4

Reduces heat loss to surroundings

Question 5

How is lubrication useful?

Answer 5

Reduces heat loss due to friction

Question 6

The less waste energy means a more __________ appliance?

Answer 6

Efficient

Question 7

What is waste energy?

Answer 7

Some supplied energy transformed into non-useful forms

Question 8

Explain energy transfers in a vehicle braking.

Answer 8

KE —> heat energy by friction in the brakes

Question 9

Explain energy transfers in a electric kettle?

Answer 9

Electrical energy —> heat energy

Question 10

Explain the energy transfers in a bungee jumper.

Answer 10

As cord stretches, KE —> Elastic potential Energy, slowing down the jumper

Question 11

Give a benefit of solar power?

Answer 11

Relatively cheap, can be used in remote areas, renewable.e

Question 12

Give a disadvantage of solar power?

Answer 12

Only possible in daylight, inefficient, high initial cost

Question 13

Give a benefit of wind power?

Answer 13

Cost effective and abundant source of energy

Question 14

Give a disadvantage of wind power?

Answer 14

Restricted by wind speeds
Visual and sound pollution

Question 15

Give a benefit of hydroelectricity?

Answer 15

Provide large quantities of energy in a short time

Question 16

Give a disadvantage of hydroelectricity?

Answer 16

Affects water life
Only a limited number of suitable sites for water dams

Question 17

Give a benefit of tidal power?

Answer 17

Renewable and predictable
High power output

Question 18

Give a disadvantage of tidal power?

Answer 18

Relatively new so costly to install and maintain
Limited to site availability
Energy demand

Question 19

Give a benefit of Bio Fuels?

Answer 19

Quickly and locally grown (renewable)
Less garbage in landfills
It is versatile

Question 20

Give a disadvantage of bio fuels?

Answer 20

Needs a lot of land which could be used for food production
Not completely clean
Possible deforestation

Question 21

Give a benefit of coal?

Answer 21

Cost effective and generation all the time
Large amounts of energy per kg of fuel

Question 22

Give a disadvantage of coal?

Answer 22

Greenhouse emissions - carbon dioxide (global warming)
Causes sulphur dioxide (acid rain)

Question 23

Give a benefit of gas?

Answer 23

Lower greenhouse emissions compared to other fossil fuels
Quick start up times allow for flexible generation

Question 24

Give a disadvantage to gas?

Answer 24

Finite resource - limited supplies of gas
Gives of atmospheric pollutants

Question 25

Give a benefit of nuclear fuel?

Answer 25

No greenhouse gases produces
Large amount of energy per kg of fuel

Question 26

Give a disadvantage of nuclear fuels?

Answer 26

Harmful nuclear waste, must be stored for years
Risk of nuclear disasters (Chernobyl)