Flashcards in P1 2 Using Energy Deck (25):
What does GEEKSLUNCH stand for?
The forms of energy
Name all the forms of energy and state where they come from.
• Chemical - energy stored in fuel (including food)
• Sound - vibrating objects
• Heat - energy released by hot objects
• Elastic potential - energy stored in a springy object when stretched or squashed
• Gravitational potential - energy of an object at a high position
• Light - by luminous objects
• Electrical - energy transferred by an electric current
• Nuclear - from radioactive decay
• Kinetic - from a moving object
How can energy be changed?
From one form to another.
When an object falls what does it gain, increase in and decrease in?
It gains speed, it increases in kinetic energy and decreases in gravitational potential energy.
What does the conservation of energy tell us?
Energy can neither be created nor destroyed. It can only be transferred from one form to another.
Show how a moving pendulum changes in forms of energy.
It starts of with gravitational potential energy at one end and is then transferred into kinetic energy as it moves and then back to gravitational potential energy.
Why does the pendulum slow down?
Due to friction, heat is created and dissipates into the surroundings.
What are the two types of energy?
Wasted energy and useful energy.
What is useful energy?
Energy transferred to where it is wanted in the form it is wanted in.
What is wasted energy?
It is energy that is not usefully transferred, friction can cause warming up which creates unwanted heat energy.
What happens to wasted energy?
It dissipates into the surroundings.
What happens to useful energy?
It is soon transferred into surroundings.
What happens as the energy becomes less useful?
It dissipates more.
Once the energy starts to dissipate into the surrounding, what can get difficult?
For it to be used in further energy transfers.
What do Sankey Diagrams show?
The amount of useful and wasted energy.
What is the formula for efficiency?
Efficiency = useful energy transferred by the device / total energy supplied to the device (x100%)
How do you show the triangle for calculating efficiency?
Useful energy at the top and efficiency and total energy along the bottom.
How can we reduce the problem of friction causing heat?
Lubricate the parts
What does a battery contain?
What does a man on a hill contain?
What does a lamp contain?
What does a moving bicycle contain?
How can you reduce the resistance of wire causing heat?
Use wires with little electrical resistance.
How can you reduce air resistance which causes energy transfer into atmosphere?
Streamline moving objects