Physics Topic 1

Kinetic energy equation

Kinetic energy = ½ mass x velocity²

Gravitational potential energy equation

Gravitational potential energy = mass x gravity x height

How to link kinetic energy and gravitational potential energy

As is falls graviational potential is transfered to kinetic and as it rises kinetic is trasnfered to gravitational potential.

There is only gravitational potential no kinetic energy.

At the bottom (assuming there is no resistance) All the graviataional potential has been transfered to kinetic. However, nothing is 100% efficient so there is always waste energy, in this case it is in the form of THERMAL energy. As a result it will not go as high (Less Ep) so will go slower (less Ek)

Equation for elastic potential energy

½ spring constant x extension²

Equation for work done

Work done (energy) = force x distance

Equation for speecific heat capacity

(and info)

Energy = mass x specific heat cpacity x temp change

Specific heat capacity is measuered in J/Kg The higher the specific heat capacity the longer it takes to heat up and cool down. It can store more energy.

Fossil fuels

How it works - Used to heat water and turn it to steam, which turns a turbine which turns a generator and transfers it to electrostatic energy.

Location issues - Gas - Anywhere theres piped gas Coal - Near coal mines Oil - near the cost

Enviromental issues - Carbon dioxide leads to global warming and sulphur dioxide leads to acid rain

Advantages - Cheap, easy to use, reliable, lots of energy made

Disadvanatges - Will run out eventually, releases co2 that contribute to global warming, reales SO2 that caused acid rain and prices are rapidly increasing

Nuclear recourses

How it works - Daioactive materials such as uranium are mined. Used to heat water and turn it into steam, which turns turbine which turns a generator and transfers it to electrostatic energy.

Location issues - Away from people near water

Enviromental issues - Dangerous waste, explosions, contamination, visual polution and noise

Advantages - no atmospheric pollution, lots of energy released

Disadvantages - Waste remains radioactive for thousands of years, expensive to run, can be very dangerous if it goes wrong

Biofuels

How it works - The thermal energy from burning wood is used to heat water and turn it to steam, which turns a turbine which turns turns a generator and transfers it to electrostatic energy.

Location issues - Lots of land

Enviromental issues - Destorys habitat

Advantages - Renewable, doesnt need special equipment, so it can be used very easily, even in poor contries, carbon neutral

Disadvanatges - Large areas of land are needed to grow enough trees

Wind

How it works - the kinetic energy of the wind turns the turbine which turns a generator and transfers it to electronic energy

Laoction issues - Exposed windy places, like moors, coasts or at see

Enviromental issues - Visual polution, noise

Advantages - renewable, No pollution, turbines

Disadvantages - Turbines can be ugly and noisey, need lots of wind

Wave

How it works - Machines that bob up and down in the waves, the kinetic energy of the wave, turns the turbine which turns a generator transfers it to electro static energy

Loaction issues - On the coast

Enviromental issues - visual pollution

Advantages - Renewable, no pollution, because nothing gets burnt

Disadvantages - Not reliable, no wind, no waves, no energy, ugly

Tidal

How it works - At high tide, we trap the water behind a dam. At low tide, the water is released, and the kinetic energy of the water, turns the turbine which turns a generator and and transfer it to electrostatic energy.

Location issues - big estuaries were dams can be built

Enviromental issues - destroys habitat, visual pollution

Advantages - Renewable, no pollutuion, reliable, cheap to run

Disadvantages - Costs a lot to build the dam, the dam may cause local flooding

Hydroelectronic

How it works - The water flowing in a river has kinetic energy it is released by the dam, the water turns the turbine which turns a generator which make the electrostatic

Location issues - Hilly, rainy places with floodable valleys

Enviromental issues - Destroys habitats, dams bursting, visual polution

Advantages - renewable, mo pollution, we can store the water up high and then whenever we need the energy we can let the water out.

Disadvanatages - costs a lot of money to build a damn, the dam can ruin the local enviroment, some amimals and plants may die.

Geothermal

How it works - Cold water is pumped below the ground, thermal energy from hot rocks heat the water, turning it into steam. The steam turns the turbine, which turns a generator which makes the electrostatic energy

Location issues - places where hot rocks are near the earths surface

Advantages - renewable, no pollution

Disadvantages - very few places in the world where you can do this, costs a lot of money

Solar

How it works - The suns energy can either be changed into electrostatic energy to use in homes, using solar cells

Enviromental issues - anywhere but sunny preferably

Advantages - renewable, no pollution

Disadvantages - expensive, only works in the sun