Physics Paper 1 Summary

8 energy stores

-Kinetic

-Thermal

-Chemical

-Gravitational Potential

-Elastic Potential

-Nuclear

-Magnetic

-Electrostatic

4 Energy Transfers

-Mechanically

-By heating

-Electrically

-Radiation

Ways to Generate Electricity

Non Renewable and Renewable Resources

Non Renewable Resources: Fossil Fuels

Fossil fuels are made out of remains of living organisms that died millions of years ago

Advantages of Fossil Fuels

They are reliable and release a great deal of energy, they are also abundant and relatively cheap and they are extremely versatile

Disadvantages of Fossil Fuels

Produces carbon dioxide which is a greenhouse gas which leads to global warming

Nuclear Energy

Releases energy form nuclear reactions

Advantages of Nuclear Energy

It is extremely reliable and does not release carbon dioxide therefore does not contribute to climate change

Disadvantages of Nuclear Power

Contains highly dangerous radioactive material and dismantling a nuclear power plant takes many years and is extremely expensive

Advantages of Wind Turbines

Wind is a naturally replenishing resource so it will not run out and they do not produce pollutants

Disadvantages of Wind Turbines

Unreliable as it is dependant on the speed of the wind

Advantages of Solar Panels

Solar panels produce electricity without emitting greenhouse gase , reducing climate change impact.

Disadvantage of Solar Panels

Dependent on the sun, so on cloudy day, its ineffective

Advantages of Wave Power

Uses turbines to produce electricity therefore does not affect climate change

Disadvantages of Wave Power

Could be harmful to marine life

Advantages of Tidal Barriers

Uses turbines that use energy from tides going up and down therefore not affecting climate change.

Disadvantage of Tidal Barriers

Can potentially kill marine life and need a suitable location to construct them

Advantages of Hydroelectric Energy

Uses turbines in a valley to generate electricity therefore not affecting climate change.

Disadvantages of Hydroelectric Power

Can only be built in limited locations and can disrupt the ecosystem by destroying habitats

Advantages of Geothermal Energy

Its renewable and provides a reliable and constant power source

Disadvantages of Geothermal Energy

Can only be used in Volcanic Areas

Advantages of Biofuels

They are produced from plant materials which are burnt however they do not add any extra carbon dioxide to the atmosphere therefore it is carbon neutral

Disadvantage of Biofuels

If we use land to grow crops for fuel, that could increase food prices

Circuit Symbols

I-V Graph: Ohmic Conductor

The current through an ohmic conductor at constant temperature is directly proportional to potential difference so you get a straight line passing through the origin

I-V Graph: Filament Lamp

As the current increases, the temperature of the filament increases so the resistance increases. This means less current can flow per unit of potential difference so the graph gets shallower.

I-V Graph: Diodes

Current will only flow in one direction as diodes have a high resistance in the reverse direction.

Thermistors

Decreased resistance when surroundings get hot and increased resistance when surroundings get cold

In series circuits, current is the ? Potential difference is ? Resistance ?

Current is the same everywhere and Potential Difference is shared between the components, Resistance increases as you add more resistors

In Parallel Circuits, the current ? The potential difference ? Resistance ?

The current is shared so it splits between branches and the Potential Difference is the same, Resistance decreases as you add more resistors.

Alternating Current is used in the ?

Uk’s Mains Supply which is 230 Volts and 50Hz

The three core cables

Live wire (Brown) containing 230V, Neutral wire (Blue) which completes the circuit (0V), Earth wire (Green and Yellow) which is for safety (0V)

The Earth Wire

Used when the live wire comes in contact with the metal casing of an appliance

The National Grid

Where electricity leaves power stations and passes through a step up transformer which increases potential difference and decreases current so that less energy is lost due to heat at the transmission cables, it is then distributed around the country and goes through a step down transformer which reduces the potential difference to 230V and increases the current in order to be passed to homes

Solid Particles

Are closely packed and are arranged in a regular pattern and vibrate and have a medium density

Liquid Particles

Are closely packed but are arranged in a irregular pattern and slide past each other

Gas Particles

Are loosely packed, not arranged in a pattern and move rapidly, they have low density

Gas Particles in a Container

The particles collide with each and the walls of the container, which creates a pressure on the container and as the temperature increases the speed of the particles increase which causes the gas particles to hit the walls of the container more often with a greater force which creates more pressure

Internal Energy

is the total energy of all the particles in a substance, including both kinetic and potential energy. It influences temperature changes.

Internal energy= ?

Kinetic Energy + Potential Energy

What is Specific Latent Heat

The energy required to change the state of 1kg of a substance without changing its temperature

What is Specific Latent Heat of Fusion

The amount of energy required to change 1kg of a substance from a solid to a liquid with no change in temperature

What is Specific Latent Heat of Vaporisation

The amount of energy required to change 1kg of a substance from a liquid to a vapour with no change in temperature.

When the state changes are happening, the temperature of the substance ?

Stays the same

When changing states, energy is used to ?

Energy is used to break bonds rather than raising the temperature

John Dalton Believed ?

Atoms are spheres where each element have different types of atoms

JJ Thompson

Discovered the electron and came up with the Plum pudding model, which contained embedded electrons in a positive sphere

Ernest Rutherford

Conducted the Gold Foil Experiment. He fired alpha particles at a thin gold foil and resulted that since most of the alpha particles passed through the foil while a few were deflected and some bounced back, the atom is mostly empty space, it is has a positive charge in the centre of the atom, the mass is concentrated in the centre known as the nucleus

Niels Bohr

Discovered that the electron orbits around the nucleus at specific distances. We call the ‘orbits’ energy levels or shells. The model was called The Planetary Model

James Chadwick

Discovered that the nucleus also contains neutrons, these have no overall charge meaning they are neutral. He came up with the modern nuclear model that we use today containing protons, neutrons and electrons

The electrons can go ?

Up energy levels by absorbing electromagnetic radiation and go down by emitting electromagnetic radiation

Mass number (Top number of element)

contains number of protons and neutrons

Atomic Model (Bottom Number of Element)

Contains number of protons and electrons

Unstable Nucleus become stable by ?

Giving off Radiation, which is known as Radioactive Decay and is a random process

Half Life

The time it takes for the number of undecayed nuclei to halve

How to measure Half life on a graph

Half life is measured using a ?

Geiger-Muller Tube and is measured in becquerels (Bq)

Contamination

when radioactive particles come into direct contact with materials

Irridation

When an object or a person is exposed to radiation

Alpha particles have a very high risk of ? and have a very low risk of ?

High risk of contamination as it is highly iosnising and low risk of irradiation as it cant travel far into air

Gamma has a high? and low ?

high irradiation risk and low contamination risk