Energy revision

Types of Energy

Chemical, heat, sound, light, kinetic, magnetic, elastic, gravitational potential.

Principal of Conservation of Energy

Energy can be changed from one form to another but the total amount of energy does not change.

Energy Measurement Unit

Energy is measured in Joules.

1 joule

Can lift an apple vertically by 1 meter.

Renewable Energy

Energy collected from resources that will never run out or are naturally replenished within a human lifetime.

Examples of Renewable Energy

Sun, wind, hydro, tidal, waves, wood/biofuel, geothermal.

Non-renewable Energy

Energy that has a finite supply and will eventually run out.

Examples of Non-renewable Energy

Coal, oil, gas.

Is Nuclear power renewable and why?

Non-renewable as supplies of uranium ore will eventually run out.

Environmental Effects of Non-renewable Energy

Can cause acid rain or global warming (greenhouse gases).

Efficiency

A measure of how much of the input energy appears as useful output energy.

Efficiency Calculation

Efficiency = Useful output energy / total input energy.

Work

When energy changes from one form to another.

Work Done Calculation

Work done = Force X Distance.

Units of Work Done

Must be in Joules, Newtons, and Metres.

Conversion of Mass to Weight

1 kilogram = 10 Newtons.

Power

The amount of Work done or energy transferred in one second.

Power Measurement

Measured in watts or joules per second.

Power Calculation

Power = energy transferred / time taken.

Kinetic Energy Formula

Kinetic energy = ½ X mass X velocity squared.

Kinetic Energy Units

Calculated using Kilograms and Metres/second.

Gravitational Potential Energy (GPE) is due to…

Due to an object's position above the ground.

GPE Formula

GPE = mgh (mass X height X gravity).

GPE Calculation Units

Using vertical height in metres and mass in Kilograms.

Insulation Against Conduction

Windows can be insulated via double glazing.

Conduction Heat Loss Prevention

Walls can have a space in the center to stop conduction heat loss.

Convection Heat Loss Prevention

Walls can have foam inside them to stop heat loss through convection currents.

Work done must be measured in these units

Joules, Newtons, and Metres.

Definition of Renewable Energy

Energy that is naturally replenished.(within the human lifetime)

Kinetic Energy depends on which factors

Mass and velocity.

Principal of Energy Conservation states that...

Energy can be changed from one form to another but the total amount of energy does not change

What can 1 joule lift?

An apple vertically by 1 meter.

What is renewable energy derived from?

Resources that are naturally replenished.(within the human lifetime)

Coal, oil, and gas are examples of...

Non-renewable energy sources.

What does GPE depend on?

An object's mass, height, and gravity.

How to improve wall insulation?

Use foam to reduce convection heat loss.

What does efficiency measure?

The useful output energy compared to input energy.

Power is defined as...

The rate of doing work or transferring energy.

What is the formula to calculate efficiency?

Efficiency = Useful output energy / total input energy.

What is the formula for work done?

Work done = Force X Distance.

What is the formula for calculating Kinetic Energy?

KE = ½ mv².

What type of energy does height create?

Gravitational Potential Energy.

How can energy from uranium be classified?

Non-renewable.

What defines renewable resources?

Resources that do not deplete over time.

How is power expressed?

In watts or joules per second.

What two conditions are used to measure GPE?

Mass in kilograms and height in meters.

What does double glazing help prevent?

Heat loss through conduction.