1. Energy Conversions

2. Do Now Questions
A 10.0 kg water balloon is dropped from a height of 12.0 m. Calculate the speed of the balloon just before it hits the ground.
A 30.0 kg child on a trampoline jumps vertically into the air at an initial speed of 1.60 m/s. Calculate how high the child will rise.

3. Energy Conversions
In daily life, energy conversions are constantly encountered
What evidence is there that energy conversions take place?
A change in position
A change in shape
A change in temperature

4. Change in Position

5. Change in Shape

6. Change in Temperature

7. Energy Conversion in Natural Systems
Photosynthesis: converts solar energy into chemical energy
Cellular Respiration: converts chemical energy into more
usable forms of chemical
energy, and eventually
into mechanical and
heat energy

8. Energy Conversion in Technological Systems
Hydro-electric dams convert moving water into electrical energy
The water is held behind a dam, which falls and turns a turbine
The turbine turns a coil of wire and forces electrons to move through the wires
The newly created electrical energy cab be used to power all sorts of things, such as residential areas
Coal and natural gas can be burned and the steam can be used to turn a turbine in a similar fashion as the water in a dam

10. Problems? http://www.youtube.com/watch?v=yqU02Wz9pbo

11. Nuclear Energy Conversions
Uranium disintegrates in a nuclear reactor, releasing nuclear energy as radiation
This radiation is converted to thermal energy, which is used to heat water to steam
The steam is piped into turbines, which generate electrical energy

14. Solar Energy Conversions
Engineers have developed technologies to harness the energy released by the sun using solar panels or solar cells

15. Solar Energy Conversions
They convert solar energy directly into electrical energy with no moving parts
They are composed of two layers of silicon, one with phosphorus and one with boron added
Electrons are bound up in the silicon crystals of the layers, and when solar energy strikes the cell, it provides enough energy that electrons are able to break free and move within the crystals
This causes the phosphorus layer to become negatively charged, and the boron layer to become positively charged
With this separation in charge, electrons begin to flow, as within a battery

16. Solar Energy Conversions

17. Fuel Cells Operates similarly to a solar cell or a battery
A Fuel Cell converts chemical energy in fuel, such as hydrogen, into electrical energy
As long as fuel is supplied, the fuel cell will continue to operate

18. Assignment Producing Electrical Energy Page 169
You need to make a line graph for each of the six sources AND a second chart that shows the percentage of the total for each source in each year.
Complete the analysis questions and hand in together.
When you’re done, work on your Transfer Task (CSI project)