1. Applied Science III Mr. Finau

2. What is Temperature?  Temperature is the measurement of how warm or cold a system is  A system means a particular area or object at a particular time

3. What are the different scales for Temperature?  o F – Fahrenheit  Primarily used in the United States  o C – Celsius  Primarily used in most countries that use the metric system  o K – Kelvin  Primarily used in scientific research

4. How do we convert among the different scales?  Celsius to Fahrenheit  Kelvin to Celsius

5. Practice  Convert from 293 o K into Fahrenheit

6. When put on a stove top, what happens to a pot of water?  Water will start to boil  Heating up the water to increase the temperature

7. What is Heat?  Heat is the transfer of energy  Temperature is related to the amount of energy in the particles that make up a system

8. Does matter have heat?  Matter contains internal energy  Heat is the transfer of energy, so matter doesn’t have heat, it just has internal energy.

9. What happens to the energy in particles when they are cooled?  Energy is transferred out of the object  Have less motion of particles  Particles have less energy  Heating and cooling are reverse processes of adding or taking away energy from molecules

10. What is meant by “A thermometer measures its own temperature”  The particles in the thermometer is brought to the same temperature as the particles around it  Thus, its measurement is really the temperature that it is brought to

11. What is Thermal Equilibrium?  A state at which all temperatures are equal  This is how a thermometer reads the temperature  This is why ice is used in drinks; ice rises in temperature as the drink lowers in temperature until they equal out

12. When using a thermometer, do you read it right away?  No, you must wait until the substance in the thermometer comes into thermal equilibrium with what you’re measuring  Thermometers are calibrated according to the expansion of the substance in it  Older ones used Mercury (very toxic); newer ones use an Alcohol mixture

13. Which is easier to heat up: A bath tub or a pot of water? Why?  It’s easier to heat up a pot of water  The more substance (ie. – the more mass), the more energy is needed to heat to a certain temperature

14. What is the Ideal Gas Law? What do each of the variables stand for?  Ideal Gas Law explains what happens to gas molecules in terms of 4 variables:  P = Pressure  V = Volume  n = number of molecules  T = Temperature

15. What would happen to an object’s volume if its temperature is increased?  As Temperature increases, Volume increases  Molecules tend to expand the area they take up as it has more energy

16. On a bridge, there is a grating or gap called an expansion joint. Explain why they are placed at certain points on a bridge.  The temperature changes as the seasons change  As the temperature changes, the volume of the bridge changes; space must be left to allow for this change in volume  Thermal Expansion – substances expand as temperature increases

17. Thermodynamics Video

18. Do all materials change volume at the same rate? Why?  Every material changes volume differently depending on how much heat is absorbed  Specific Heat – the amount of heat needed to raise the temperature of a material by 1 degree

19. How does a thermostat in a house work?  Uses a bimetallic strip  Two metals fused onto each other  As temperature increases, 1 metal expands faster than the other, causing the strip to bend and touch a sensor

20. When cooking, why do people say to run a jar’s lid under hot water?  The metal lid will expand quicker than the glass jar, loosening the lid.

21. What would happen to the pressure of gas if its temperature is increased?  As the temperature increases, the pressure increases as well  In a closed container, expanding gas can break through

22. Vice versa, what happens to the pressure of gas if its temperature is decreased quickly?  When the temperature decreases rapidly, the gas pressure inside decreases quickly too  The pressure outside the container is then greater, and the container can be crushed

23. If you put a hot object in contact with a cold object, what happens? Which way does heat flow?  The hot object cools down; the cold object heats up  Conduction – transfer of energy through contact between objects  Heat always flows towards colder areas  A cold area cannot randomly transfer energy to a hot area

24. Pressure Video