year 9 physics

Name the 8 main energy stores

GPE, kinetic, elastic, magnetic, electrostatic, thermal, chemical and nuclear

Name the 4 main energy transfers

Heat, work done, electrical and radiation

What is GPE?

Gravitational potential energy - energy stored in a mass within a gravitational field

What is kinetic energy?

Energy stored in an moving mass

What is elastic potential energy?

Energy stored in an elastic object

What is magnetic energy?

Energy stored in a magnetic object within a magnetic field

What is electrostatic energy?

Energy stored in a charged object in an electrostatic field

What is thermal energy?

The total kinetic and potential energy of particles in an object

What s chemical energy?

Energy stored in chemical bonds such as between molecules

What is nuclear energy?

The energy stored in the nucleus of an atom

Examples of magnetic stores?

Maglev trains, compasses and fridge magnets

Examples of thermal stores?

Human bodies, hobs, hot coffee

Examples of chemical stores?

Food, muscles, electrical cells

Examples of kinetic stores?

Runners, buses, comets

Examples of electrostatic stores?

Thunderclouds, Van De Graaff generators

Examples of elastic stores?

Compressed springs, inflated balloons, drawn catapults

Examples of gravitational stores?

Aeroplanes, mugs on a table, kites

Examples of nuclear stores?

Nuclear reactors, uranium nuclear power

What is the mechanical work transfer?

A force moving an object through a distance

What is an electrical work transfer?

Charges moving due to a potential difference

What is a heating transfer?

Due to temperature difference caused by electric or chemical reactions

What is a radiation transfer?

Energy transferred as a wave (like infrared radiation from the sun)

What are SANKEY diagrams?

Diagrams that start off as one arrow that splits into 2 or more points. To show how all of the energy in a system is transferred into different stores.

Why are SANKEY diagrams useful?

The width of the arrow is drawn to scale to show the amount of energy, you can also figure out waste energy.

What is the law of conservation of energy?

Energy cant be created or destroyed, however it can be transferred from one energy stored in an to another

What is the work done equation?

Work done (J) = force (N) x distance (m)

What is a trundle wheel?

A device for measuring distance on a larger scale.

What is power measured in?

Watts

What is the equation for power?

Power = energy/time

What do all plantes have?

A gravitational field caused by its mass

What is the symbol for gravitational field strength?

g

What s the gravitational field strength on earth?

9.8 N/kg

What is weight caused by?

Gravity

What is the weight equation?

Weight = mass x gravitational field strength

What is the question for the change in GPE?

Change in GPE = mass x g field strength x change in height

What two things give an object more kinetic energy?

Mass and velocity

What is the kinetic energy equation?

Kinetic energy = ½ x mass x velocity**2

What is an elastic object?

One that will go back to its original shape once the forces changing it are removed

3 formes of elastic change?

Compression, tension and bending

What happens when you stretch a band?

The work you do in energy is stored in the band as elastic potential energy.

What is the extension equation?

Extension = extended length - original length

What is the stretching force called?

The load

What is the elastic potential energy equation?

EP = ½ x spring constant x extension**2

What is K EP?

The stiffness of a spring

What is useful energy?

Energy transferred into the desired from for a specific purpose

What is wasted energy?

Energy not useful transferred

What is an example of wasted energy?

Heat energy wasted from a TV

Useful and wasted energy from an electric kettle?

Useful - thermal energy

Waste - sound energy and unused water

What happens to wasted energy?

It dissipated into the surroundings as a thermal store - the more it spread out the less useful it becomes