Elastic Energy
True or False. A spring has elastic energy.
True
What is energy?
The ability to do work.
Is chemical energy potential or kinetic?
Potential energy.
What is the SI unit of energy?
Joules
State the formular for potential energy.
Ep = mgh
Is elastic energy, kinetic or potential?
List the four types of potential energy
Chemical, Nuclear, Elastic, Gravitational potential
State the energy transformation(s) for a battery powering a torchlight. (Only include the useful energy)
Chemical --> Electrical --> Light
How much energy does a ball have if it is raised off the ground 1 m, and has a mass of 1 kg.
9.8 J
State the formula for kinetic energy.
Ek = 0.5 mv2
Define elastic enegy
State the law of conservation of energy.
Energy cannot be created, nor destroyed. Only transformed from one type to another.
State the energy transformation for a person eating food and then going for a run. State the useful & wasted outputs.
Chemical --> Movement (useful) + Heat (wasted) + Sound (wasted)
Convert 8000 j into kilojoules.
8 kj
What is the difference between an energy transfer and energy transformation?
Transformation: Different forms of energy going from one object to other.
A pulled back elastic band, is let go. State the energy transformation.
Elastic transformed into movement.
List the 5 types of kinetic energy.
Movement, Electrical, Light, Thermal, Sound
State the reaction that releases the chemical energy stored in fuels.
Combustion reaction.
Convert 6 MJ into Joules
6 000 000 J
Explain what is happening (in terms of max. kinetic and max. potential energy) when a ball is thrown up.
Max Ek when ball is thrown, max Ep at the top of the throw.
State the useful and wasted energy from a compressed spring, being released.
Useful: Movement
Wasted: Sound, Heat
State the particles that are moving in the following types of energy:
1. Electrical
2. Light
1. Electrons
2. Photons
Challenge: State the combustion reaction.
Fuel + Oxygen --> Carbon dioxide + Water
Re-arrange potential energy formula, to find height.
h = Ep/
Explain what a Sankey diagram shows and explain its shape.
Sankey diagram shows input energy (on the tail/left of the arrow), and the output energy (on the right/head of the arrow). The useful energy points straight, and the wasted points downwards.