Unit B – Energy Transformations. Chapter 5 – Energy Transformations. In this chapter you will learn: how to identify different types of energy that some energy conversions absorb energy and some release it how energy is converted and that energy is lost with each conversion
solar chemical kinetic
(photosynthesis) (cellular respiration)
solar wind electricity
When energy is converted from one form to another, thermal energy is produced
Turbines and Generators
In order to make electricity, turbines need to be connected to a generator.
into electrical energy
What are some of the advantages and disadvantages of producing electricity with nuclear energy?
Japan Nuclear Reactor Explanation
power is measured in Watts (W)
energy is measured in Joules (J)
time is measured in seconds (s)
An aquarium light bulb uses 7 J of electric energy in one second. How many watts of power does it consume in 3 seconds?
Speakers on a computer use 40 J of electric energy. How many watts of power do the speakers consume in one minute (60 seconds)?
You can calculate how much electric energy is consumed by a device by re-arranging the formula:
Where energy is measured in watt hours (Wh)
power is measured in watts (W)
time is measured in hours (h)
How much electric energy does a 60 W light bulb use if it is left on for 2 hours?
How it’s Made: Fluorescent Bulbs
How it’s Made: Incandescent Bulbs
NatGeo energy efficient bulbs
An electric kettle uses 240 000J to heat water. 196 000J is actually used to heat the water. What is the efficiency of the kettle?
solar chemical potential
Animals convert the chemical potential energy in plant and animal cells into mechanical energy
chemical potential mechanical
Animals can get energy from eating plants or from eating other animals
Only 10% of energy is transferred to the next level as it moves through an food chain
be supported with
How fossil fuels form
CH4 + O2 CO2 + H2O + energy
Both cellular respiration and the burning of fossil fuels use hydrocarbons as a fuel source
The combustion of fossil fuels releases large amounts of CO2 into the atmosphere