1. Energy and Matter
All physical phenomena are governed by the laws of conservation of energy and matter

2. Energy is classified into three main forms Radiant Kinetic & Potential

3. This is energy from the Sun which is the result of nuclear fusion
Radiant Energy
This is energy from the Sun
which is the result of nuclear fusion

4. Kinetic Energy
This is the energy carried by objects in motion, like a locomotive.
Kinetic Energy includes:
1. Mechanical energy carried by the moving parts of a machine
2. Thermal Energy of the random internal motion of particles in all substances

5. Calculate the KE of a 70kg man walking at 2.5m/s. m=mass v=velocity
KE =1/2 mv2
Calculate the KE of a 70kg man walking at 2.5m/s.
m=mass v=velocity

6. KE= ½ mv2 KE= ½x 70x(2.5)2 KE = ½ x 70x 6.25 KE=218.75 Joules
m = 70kg
v = 2.5 m/s
KE = ?
KE= ½ mv2
KE= ½x 70x(2.5)2
KE = ½ x 70x 6.25
KE= Joules

7. Potential Energy
This is the energy possessed by objects because of the position or the arrangement of their particles
In essence it is stored energy.

8. Gravitational Potential Energy
The kind of energy carried by water before it falls through the spillway of a hydroelectric dam is called gravitational potential energy.
Gravity is responsible for converting the potential energy of the water into kinetic energy , which is then able to do work

9. PE= m g h M=mass g=gravity (9.8m/s2) h=height
What is the gravitational potential energy of a 2 kg ball at rest on a window sill, 40m up from the pavement?

10. PE=m g h m=2kg h= 40m g=9.8m/s2 PE = 2kg x 40m x 9 .8m/s2
PE = 784 Joules

11. Other forms of Potential Energy
Electrical Energy
is the energy that exists when objects with different electrical charges are separated. Batteries operate on this principle

12. Chemical Energy
is the energy which exists in some substances because of the arrangement of their particles.
Fuels and food contain Chemical Potential Energy

13. Measuring energy The common unit of energy is the calorie (cal)
1 calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius

14. The SI Unit of energy is the Joule (J)
Joule in the long form is kg.m2/s2
4.184J = 1 cal
4.184 KJoule = 1Kcal or 1Cal
How many kilojoules are there in an average size chocolate bar that has 200 Cal?

15. Energy stored in food is often given a unit that is related to the calorie. The Calorie (Cal) is 1000cal or 1 kilocalorie.

16. 1cal =4.184 joules chocolate bar=200 Cal 200Cal x 4.184 KJ/Cal=
Energy in one chocolate bar= 836.8KJ

17. Law of Conservation of Energy
The law of conservation of energy states that energy can neither be created nor destroyed, it simply changes from one form to another

18. The energy crisis
Q.If energy is neither created nor destroyed, then how could we run out?!

19. A. Our society relies on coal, natural gas & petroleum (crude oil) for about 90% of its energy needs.

20. Why is Coal and Petroleum so valuable?
They are simple to get and use –we dig them or pump them and burn them!
Burning releases their chemical energy
The energy for these sources can be obtained from wind and solar, but its less convenient and more expensive.

21. Other non-fuel uses for petroleum include:
Plastics
Pharmaceuticals
Ethanol
Synthetic fibers
PVA glue

22. Alternative Energy Sources
More research and development will be needed to decrease out need for the energy we derive from fossil fuels.
Conservation and reduction of individual use can contribute to the availability of fossil fuels into the future while alternatives are perfected.

23. Measure of the average KE of the particles in a sample.
2-2 Temperature
Measure of the average KE of the particles in a sample.
Can be measured directly.

24. Thermometer
The modern thermometer used in our class is filled with colored alcohol.
As the bulb is heated or cooled the liquid with expand or contract.

25. The Celsius Temperature Scale
The freezing point of pure water at sea level is 0º C.
The boiling point of pure water at sea level is 100º C.

26. Kelvin Temperature Scale
SI Unit for temperature is Kelvin (K).
The degree unit is not used in Kelvin (K),

27. The Difference between Kelvin and Celsius
The main difference is the location of the zero point.
The zero point for kelvin is called absolute zero.
Absolute zero is equal to -273º C.
Absolute zero is the point at which the motion of particles of matter has completely stopped.

28. Converting Kelvin and Celsius
ºC = K – 273
K = ºC + 273
For example, the boiling point of water is 100 ºC is 373 K.
K = 100 ºC + 273
K = 373 K

29. Convert 50. K to the Celsius scale
ºC = K – 273
ºC = 50. K – 273
ºC = -223 ºC

30. Converting Fahrenheit to Celsius
ºC = (ºF – 32) x 5/9
Convert 67F to C
ºC = (67º – 32) x 5/9 = 19.4 ºC

31. Converting Celsius to Fahrenheit
ºF = (9/5 x ºC) + 32
Convert -14 ºC to ºF
ºF = (9/5 x -14º) + 32 = 6.8ºF