1. Energy coloradohomeperformance.org

2. What is Energy? en.wikipedia.org guardian.co.uk blogs.westword.com
insight.rit.edu stuffyoudontwant.com

3. Law of Conservation of Energy
In any process, energy is neither created nor destroyed.
In any situation, energy is transferred from one object to another or transformed from one kind of energy into another kind.
Ex. Striking a match transfers chemical energy into heat and light.

4. Conservation of Energy and Calorimeters
In our specific heat lab the heat gained by the water was assumed to equal the heat lost by the metal. We would need a much better calorimeter for this to be so.

5. Types of Energy
Kinetic Energy- Energy carried by objects in motion (ex. moving car, kicked ball)

6. Types of Energy
Potential Energy- Energy possessed by objects because of their position or the arrangement of their particles. (ex. batteries or apple on tree)

7. Types of Energy
Heat Energy - Energy that is in the process of flowing from a warmer object to a cooler object.

8. Measuring Energy
Unit of energy is a calorie (cal). One calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1 Celsius degree.
This definition above refers to “small calorie”
Calorie, is the dietary reference for which we use to describe food. Notice the capital C.
The SI unit for energy is the joule.
1 cal = J
1 Calorie = 1 kcal =1000 cal
1 Calorie = 4184 J

9. Conversion Problem
How many joules are there is the burger from the previous slide? Remember 1 Calorie = 4184 J.

10. Temperature
Humans perception of temperature isn’t precise, so we must use a thermometer to measure temp.
Temperature can be measured in either Fahrenheit, Celsius, or Kelvin.
Celsius scale more compatible with the metric system than Fahrenheit scale.
The SI scale used to measure temperature is the Kelvin scale.
igemwatch.net

11. Why the Kelvin Scale
In 1848 William Thomson (later known as Lord Kelvin) was studying gas laws.
It had been known that the temperature and pressure of gasses effected each other directly
An increase in temp would result in an increase in volume and vice versa.

12. Temperature and Volume
If temperature decreases so does volume of the gas.
At what temperature would the volume decrease to become zero?
Kelvin calculated this to be -276 C. He called it Absolute Zero.
We now know Absolute Zero is -273 C
Not bad for a guy working by oil lamp!!!

13. Absolute Zero
The pursuit of obtaining a temperature of absolute zero, 0 K or -273°C.
Is it possible to reach absolute zero?
In theory no, it is unattainable because as atoms begin to lose energy, they slow done. So at 0 K, they would lose energy completely.
The problem is that as atoms are pushed closer together, its harder to remove any heat.

14. Temperature Conversions
F = (C x 9/5) + 32
C = ((F - 32) x 5)  9
K = C + 273
C = K -273
What is the temperature outside in C in it is 84 F?
(84-32)= 52 x 5 = 260  9 = 28.9 C

15. Conversion Problem
How many calories are in 42.5 Calories? (1 Cal = 1 kcal= 1000 cal)

16. More Conversions…
Convert 67 C to K.
Convert 100F to K.

17. Even More Conversions!
Convert 245 Degrees Fahrenheit to Kelvin First we convert from Fahrenheit to Celsius (F – 32F)*(5C/9F) = C (245F - 32F) * (5C/9F) = 118C Second we convert from Celsius to Kelvin C = K 118 C = 391 K