Section 1 of 17Energy Stores & Transfers
These all
- These all These all describe the different ways that energy and matter may interact with a system and the surroundings
Pulling, pushing,
- Pulling, pushing, pulling, pushing, stretching, squashing) Electrical working A charge moving through a potential difference (e.g
Current) heating
- Current) heating current) Heating (by particles) Energy is transferred from a hotter object to a colder one (e.g
Conduction) (heating
- Conduction) (heating conduction) (Heating by) radiation Energy transferred by electromagnetic waves (e.g
They
- They are there to help you keep your answers concise so you don't end up wasting time in your exam
Section 2 of 17Examples of Energy Transfer
1
Fundamental principles, definitions, and physical or chemical laws governing this topic.
2
Key interactions, structural properties, and process dynamics observed in experiments.
3
Quantitative relationships, key formulas, and criteria required by specification mark schemes.
Section 3 of 17Kinetic Energy
Kinetic Energy
Calculate the
- Calculate the Calculate the mass of the skateboarder
Forgetting to do this
- Forgetting to do this is the most common mistake that students make
Two other common slips
- Two other common slips are leaving out the ½ and writing kinetic energy as mass × speed
The equation
- The equation is given on the Physics Equations Sheet, so copy it carefully
Always square
- Always square Always square the speed before you multiply by the mass Do not leave out the ½ and do not use E = m × v If the question gives you the kinetic energy, substitute it into the equation and solve for the unknown Check the unit of each value before you substitute k
Section 4 of 17Gravitational Potential Energy
Jupiter and Saturn)
- Jupiter and Saturn) is more than on the Earth This means it would be harder to lift a mass on the gas giants than on the Earth Some values for g on the different objects in the Solar System Worked Example A man of mass 70 kg climbs a flight of stairs that is 3 m higher than the floor
Gravitational field strength
- Gravitational field strength is approximately 9.8 N/kg
Calculate the
- Calculate the Calculate the energy transferred to the man's gravitational potential energy store
The person
- The person The person has a mass of 60 kg and g = 9.8 N/kg
Calculate the
- Calculate the Calculate the change in vertical height
Section 5 of 17Elastic Potential Energy
1
It stretches from 10.0 cm to 11.4 cm
2
Calculate the elastic energy stored by the stretched spring
3
If the question gives the extension in cm, you must convert it into metres for the calculation to be correct
4
Remember to square the extension before multiplying by the spring constant
5
is squared, not k or ½
Section 6 of 17KE, GPE & EPE
KE, GPE & EPE
The bungee
- The bungee The bungee cord has an unstretched length of 30.0 m
The mass of the student
- The mass of the student is 60.0 kg
The gravitational
- The gravitational The gravitational field strength is 9.8 N/kg
The car
- The car The car has mass 0.052 kg
Calculate the
- Calculate the Calculate the maximum speed of the car
Section 7 of 17Thermal Energy
You will
- You will You will always be given the specific heat capacity of a substance, so you do not need to memorise any values
Use the
- Use the Use the temperature change, not the final temperature
Convert kj
- Convert kj Convert kJ to J and g to kg before substituting
Section 8 of 17Required Practical: Investigating Specific Heat Capacity
1
Measure the mass of the aluminium block using a balance 2
2
Start by assembling the apparatus, placing the heater into the top of the block 3
3
Leave the thermometer in the block for a few minutes so that it reaches the same temperature as the block, then measure the initial temperature 4
4
Turn on the power supply and start the stopwatch 5
5
is on, the heater will heat up the block
Section 9 of 17Changes in Energy
Changes in Energy
Changes in
- Changes in Changes in Energy Changes make things happen
They
- They are there to help you keep your answers concise so you don't end up wasting time in your exam
If you
- If you If you follow any process back far enough, you would get many energy transfers taking place
For example,
- For example, For example, an electric kettle heating water
The relevant energy transfer
- The relevant energy transfer is from the thermal store of the kettle to the thermal store of the water, with some energy dissipated to the surroundings
Section 10 of 17Power
Cover up
- Cover up Cover up the quantity to be calculated
This is
- This is this is known as the 'subject' of the equation 2
Drawing the
- Drawing the Drawing the formula triangle does not score the mark
Use the
- Use the Use the triangle to rearrange, then write the equation out in full and define each symbol
But if
- But if But if one of them does it in a shorter time, it will have a greater power Worked Example Calculate the energy transferred when an iron with a power rating of 2000 W is used for 5 minutes
Section 11 of 17Conservation & Dissipation of Energy
1
Fundamental principles, definitions, and physical or chemical laws governing this topic.
2
Key interactions, structural properties, and process dynamics observed in experiments.
3
Quantitative relationships, key formulas, and criteria required by specification mark schemes.
Section 12 of 17Wasted Energy
Wasted Energy
The motor
- The motor The motor turns a mechanism that lifts the load
Some of the energy transfers
- Some of the energy transfers are useful and the rest of the energy is wasted
A) state
- A) state a) State the useful energy transfer occurring in this system
B) state
- B) state b) State the wasted energy transfer occurring in this system
When describing
- When describing When describing wasted energy, make sure to say the energy is transferred or dissipated to the surroundings
Section 13 of 17Conduction of Heat
Core Concept
- Core Concept Fundamental principles, definitions, and physical or chemical laws governing this topic.
Mechanism & Behavior
- Mechanism & Behavior Key interactions, structural properties, and process dynamics observed in experiments.
Exam Applications
- Exam Applications Quantitative relationships, key formulas, and criteria required by specification mark schemes.
Section 14 of 17Required Practical: Investigating Insulation
1
Set up the apparatus by placing a small beaker inside the larger beaker 2
2
Fill the small beaker with boiling water from a kettle 3
3
Place a piece of cardboard over the beakers as a lid
4
have a hole suitable for a thermometer and place the thermometer through this hole and into the water in the small beaker 4
5
Record the temperature of the water in the small beaker and start the stopwatch 5
Section 15 of 17Efficiency
Efficiency
It lifts
- It lifts It lifts a 7.2 kg load through a height of 5 m in 3 s
Gravitational field
- Gravitational field Gravitational field strength = 9.8 N/kg
Calculate the
- Calculate the Calculate the power of the motor
Answer
- Answer Step 1: List the known quantities Efficiency = 35% Mass of the load, m = 7.2 kg Height, h = 5 m Time, t = 3 s Gravitational field strength, g = 9.8 N/kg Step 2: Write down the efficiency equation This equation is given on the Physics Equations Sheet
When you
- When you When you calculate a power or an energy from an efficiency (for example 0.75 × 0.24 W), do not multiply the final answer by 100
Section 16 of 17Improving Efficiency
Remember, the
- Remember, the Remember, the efficiency of a device is improved by increasing the useful energy transfers and reducing the wasted energy transfers
In improving
- In improving In improving efficiency questions, context is key
The methods required
- The methods required are different for different situations
There
- There is no short cut to learning this, you just have to practise being able to recall the correct information for the given scenario
Vague terms
- Vague terms Vague terms like 'reducing the energy dissipated to the surroundings' will not be enough to gain you the marks
Section 17 of 17Exam Checklist & Tips
Specification Mastery Checklist
- Key Definitions Ensure precise recall of terms and units as required by examination mark schemes.
- Equations & Formulas Double-check balanced state symbols, subscripts, and SI unit conversions.
- Common Misconceptions Verify experimental conditions, controls, and comparative trends across groups.