P1 Energy

Question 1

Describe the specific heat capacity practical

Answer 1

• SHC is the amount of energy required to increase 1kg of a material by 1c
• Use a copper block wrapped in insulation
• Place holes in copper block to put thermometer with water (improved thermal contact) and heater in so heat is evenly distributed and not lost (insulation)
• Connect heater to power supply with ammeter and voltmeter
• Use ammeter and voltmeter to calculate power (v x i)
• Measure temperature every minute
• Calculate work done using power calculation ( p x time)
• Repeat with different materials other than copper
• smaller shc ; less energy needed ; bigger temperature increase

Question 2

Define a system and the effect of changes in a system

Answer 2

System = an object / group of objects

Changes in a system = changes in how the energy is stored

Question 3

Define internal energy and the effect of doing work on a system

Answer 3

• Total kinetic and potential energy of particles making up a system
• Doing work on a system increases energy stored

Question 4

What is the effect of heating a system?

Answer 4

• Energy increases, increasing the temperature or changing state
• Increase depends on mass of substance heated, type of substance and energy in put

Question 5

What happens in a closed system?

Answer 5

• total energy never changes

- transferred between stores

Question 6

How can you reduce unwanted energy transfers that waste energy?

Answer 6

• lubrication (reduces friction)
• tightening loose parts (prevents unwanted vibration that wastes energy as sound)
• thermal insulation (reduces heat loss)

Question 7

What effects the rate of cooling of a system (e.g building)

Answer 7

• thickness (of walls)
• thermal conductivity
• thin walls with high thermal conductivity will conduct heat the quickest so the building will cool down the quickest

Question 8

Name 7 renewable energy resources

Answer 8

Biofuel, wind, water (hydroelectric), geothermal, tidal, solar, water waves

Question 9

Name 4 non-renewable (finite) resources

Answer 9

Nuclear fuel, coal, oil, gas

Question 10

What are the main uses of biofuel and it’s environment impact?

Answer 10

• Transport and electricity

- large areas of land needed to grow crops, so food crops can’t be grown for poorer countries

Question 11

What are the main uses of wind and it’s environment impact?

Answer 11

• electricity

- not a constant source, turbines can be noisy/dangerous to birds, ruins appearance of countryside

Question 12

What are the main uses of hydroelectricity and it’s environment impact?

Answer 12

• electricity

- large areas of land have to be flooded that can alter eco systems and communities that live there

Question 13

What are the main uses of geo fuel and it’s environment impact?

Answer 13

• electricity and heating

- only available in places where hot rocks are close to the surface (eg Iceland)

Question 14

What are the main uses of tidal and it’s environment impact?

Answer 14

• electricity

- tide variation changes so effects output; high set up cost; alters habitats and causing shipping problems

Question 15

What are the main uses of solar and it’s environment impact?

Answer 15

• electricity and some heating

- light intensity reliant so no power produced at night; high cost in relation to power output

Question 16

What are the main uses of water waves and it’s environment impact?

Answer 16

• electricity

- output depends on waves, unreliable, alters habitats

Question 17

What are the main uses of nuclear fuel and it’s environment impact?

Answer 17

• electricity, military transport

- radioactive waste (no other emissions), costly to build and decommission, reliable

Question 18

What are the main uses of coal and it’s environment impact?

Answer 18

• electricity, heating, some transport

- produces greenhouse gases (CO2) and contributes to acid rain (SO2) but is reliable

Question 19

What are the main uses of oil and it’s environment impact?

Answer 19

• transport and heating

- reliable and compact; burning produces co2, no2 and so2, damaging of split

Question 20

What are the main uses of gas and it’s environment impact?

Answer 20

• electricity, heating and some transport

- reliable and doesn’t produces so2 but does produces co2

Question 21

Describe the specific heat capacity practical

Answer 21

APPARATUS

• copper block with holes (heater and thermometer + water)
• insulation
• power supply with ammeter and voltmeter

METHOD
- measure start temp
- switch on heater
- measure end temperature 
- use ammeter and voltmeter to calculate power P=VI
- Calculate work down WD=Pt
- repeat for different metals
smaller SHC = less energy needed = bigger temp increase

Question 22

Describe the thermal insulators required practical

Answer 22

• wrap 4 test tubes in different types of insulation
• fill each test tube with hit water and measure start temp
• record temperature every minute for 10 minutes (stopwatch)
• plot time against temperature
• cooling curve will be a smooth curved line - sudden increase or decrease should be regarded as anomalous