Energy Transformation
What is the law of conservation of energy?
Energy is never created or destroyed, only transferred or transformed.
Give two examples of renewable energy sources.
Solar, wind, hydro etc.
Name two fossil fuels
Coal, natural gas, Petrol (oil)
What is a generator
A device that produce electricity
Give an example of an energy transformation in daily life.
Identify the energy input and output
Which renewable energy source relies on the Sun?
Solar
What is greenhouse effect
Layer of greenhouse gas such as carbon dioxide retains heat from the sun.
What type of energy transformation occurs in generators.
Mechanical / Kinetic energy -> Electrical Energy
What type of energy transformation occurs in a battery-powered flashlight? (Need to list all three types of energy)
Chemical Energy -> Electrical Energy -> Light Energy
What is a key difference between renewable and non-renewable energy?
Renewable energy restored quickly or is unlimited
What is the consequences of burning fossil fuels.
Causes pollution and climate change
How does a wind turbine generate electricity?
Wind causes turbines to move -> Kinetic Energy collected -> Transform into electrical energy
A ball is dropped from a height. What type of energy transformation occurs as it falls?
Gravitational Potential Energy -> Kinetic Energy
Why are fossil fuels considered non-renewable?
Fossil fuels need a very long time to restore.
How does burning fossil fuels contribute to climate change.
Burning fossil fuels releases additonal carbon dioxide, which thickens the grrenhouse gas layer and retains additional heat.
Name a power source that doesn't need a generator to produce electricity
Solar
Calculate energy efficiency of the following scenario:
5000J of electrical energy input results in 200J energy transformed into light in the light bulb.
4%
Describe two disadvantages of wind energy.
Taking too much land and can be only built in rural area.
Depending on the weather.
Climate change -> Warmer seasons during summer -> More ice melts -> rising sea levels -> Less land for agriculture.
Describe how a coal plant generate electricty.
Burning coal -> Produce heat -> Heat water to boil -> Steam causes turbine to move -> Generate electricity.