Thermodynamics, Temperature, Temp conversions

CH 15& 16Be sure the volume is working

on your computer or laptop

View this as a slide show

Thermodynamics

• Thermodynamics – the study of conversions between thermal energy and other forms of energy.

1st Law of thermodynamics• Energy is conserved in a system• Click here to find out another way to define the first law of Thermodyn

amics

2nd law of thermodynamics• Thermal energy always moves from a warmer place to a cooler place

EX: hands around a mug of hot chocolate- the heat moves from hot chocolate to your hands

• It only happens in reverse if WORK is done on the object or system EX: air conditioner motor blows out cold air into heated room

• Click here and scroll down to “the rest of the story” and define second law of thermodynamics

What is Thermal Energy?

• Put on your headphones and click the link below to watch the short video clip over thermal energy.

• Be sure to follow along, there are questions on your assignment sheet to answer.

• The video will stop( at about 3:00 minutes) before you are able to answer questions 11-13. That’s OK! Just leave those blank and move on!

• Click here to watch- Thermal Energy

Heat Transfer

• Keep your headphones on.• Click on the link below and watch the tutorial• Be sure to follow along and answer the questions on

your assignment sheet.• After the first slide- click on the NEXT button in the

lower right hand corner to continue the tutorial.• CLICK HERE TO LEARN ABOUT HEAT TRANSER

Water movement

Hot water rises

Cooler water sinks

Convection current

Cools at the surface

Temperature and Heat• Kinetic energy is the energy of motion• Temperature : a measure of the average

amount of kinetic energy amongst the atoms in a substance.

–more Kinetic Energy -> higher temperature

–less Kinetic Energy -> lower temperature

There are 3 temp scales• Fahrenheit is the temperature scale we use for

our weather- water freezes at 32.0ºF and boils at 212.0 ˚F

• Celsius “centigrade” is the metric scale for measuring temperature- if you live in Europe you’d love it if the temperature was 27 ºC- Water freezes at 0ºC and boils at 100ºC

• The Kelvin scale the SI base unit for temperature (K)- like the meter is the base unit for length

• Water freezes 273 K – boils 373 K

Converting from one scale to another

a) K = °C + 273b) °C = K – 273c) °F = (°C 1.8) + 32

d) °C = ° F – 32 1.8

PRACTICEA. How warm would it be in Europe if the temperature was

27°C. Convert to Fahrenheit.• First choose the third Equation• Write it down.• Plug the 27 into the spot where there is °C.• Put this into your calculator.• Record the answer!

B. Convert 45 °Celsius to Kelvin• First choose the first Equation• Write it down.• Plug the 45 into the spot where there is °C.• Put this into your calculator.• Record the answer!

More PracticeC. Convert 354.0 K to degree Celsius

• First choose the second Equation• Write it down.• Plug the 354.0 into the spot where the K is.• Put this into your calculator.• Record the answer!

D. Convert 99.0 degree Fahrenheit to Celsius.• First choose the fourth Equation• Write it down.• Plug the 99.0 into the spot where the °F is.• Put this into your calculator.• Record the answer!

And More PracticeE. Convert 376 K into Fahrenheit.

• choose the second equation.• Write it down.• Put the 376 where the K is.• Plug into your calculator.• Record this answer.• NOW: choose the fourth equation.• Place your answer where the °F is.

• Plug into your calculator. • Record your answer!