P1: Energy

What are the 8 energy stores?

Kinetic

Gravitational Potential

Elastic Potential

Thermal

Nuclear

Chemical

Magnetic

Electrostatic

What are the 4 ways energy can be transferred?

Mechanically

Electrically

Heating

Radiation

What is a system?

An object or group of objects

What happens when a system changes?

Energy is transferred

What is work done?

Energy transferred when a force moves an object

What is kinetic energy?

Energy from movement

What 2 things does kinetic energy depend on?

Mass and speed

What is the formula to calculate kinetic energy?

Ek = 1/2 x m x v2

What is gravitational potential energy?

Energy from height

What is the gravitational field strength of Earth?

9.8 N/kg

What is the formula to calculate gravitational potential energy?

Ep = m x g x h

What is elastic potential energy?

Energy from stretching or squashing an object

What is the formula to calculate elastic potential energy?

Ee = 1/2 x k x e2

Define specific heat capacity.

The amount of energy needed to raise the temperature of 1kg of a substance by 1 degree celsius

What is the equation to calculate specific heat capacity?

E = m x c x

What is the independent variable in the SHC practical?

Material used

What is the dependent variable in the SHC practical?

Temperature change

What are the control variables in the SHC practical?

Starting temperature

Potential difference

What 5 pieces of equipment are needed for the SHC practical?

Block of material

Power supply

Heater

Thermometer

Insulation

What should you do to improve precision of results from a practical?

Repeat several times and calculate a mean

What does the law of conservation of energy state?

Energy cannot be created of destroyed, only stored or transferred

T or F: all energy is transferred usefully when energy is transferred between stores.

F - some energy is always dissipated when an energy transfer takes place

What is another name for dissipated energy?

Wasted energy

What is power?

The rate of energy transfer or the rate of doing work

What are the two equations that can be used to calculate power?

P = E/t

P = W/t

What is energy and work done measured in?

Joules (J)

Define conduction.

The process where vibrating particles transfer energy to neighbouring particles.

What state of matter does conduction usually occur in?

Solid

What energy store is energy transferred between during conduction?

Kinetic

Define thermal conductivity.

A measure of how quickly energy is transferred through a material by conduction.

Define convection.

Convection is where energetic particles move away from hotter to cooler regions

What two states of matter does convection happen in?

Liquid and gas

How is convection current created?

Warm and less dense air will rise above the denser, cooler air

Give an example of when convection currents are used.

Radiators

How does lubrication reduce unwanted energy transfers?

Reduces frictional forces

How does insulation reduce unwanted energy transfers?

Slows rate of energy transfer so less heat is lost

What is the formula to calculate efficiency as a percentage using ENERGY?

(Useful energy output / total energy input) x100

What is the formula to calculate efficiency as a percentage using POWER?

(Useful power output / total power input) x100

What are the two types of energy resources?

Renewable and non-renewable

What are coal, oil and natural gas?

Fossil fuels

Give two disadvantages of fossil fuels.

They are finite (they will run out one day)

They produce lots of greenhouse gases that damage the environment

Give one advantage of fossil fuels.

They are reliable

What are the 7 renewable energy sources?

Solar

Wind

Waves

Hydroelectricity

Tided

Geothermal

Biofuel

Why don't people like wind turbines?

They are noisy and ruin the view of countrysides

Why do lots of people not use solar panels?

They are expensive and unreliable because it isn't always sunny

What is one disadvantage of geothermal energy?

There aren't many suitable places to build geothermal power plants