Presentation is loading. Please wait.

Presentation is loading. Please wait.

Energy Energy – ability to do work

Similar presentations


Presentation on theme: "Energy Energy – ability to do work"— Presentation transcript:

1 Energy Energy – ability to do work
Earth two sources of energy: - external – the Sun - internal – radioactivity Electromagnetic Energy – energy given off in waves - Energy is only given off if the temperature is above absolute zero (-273oC or 0 K)

2 Solar Energy The sun delivers heat energy to Earth’s surface.
This is called radiation. This heat energy is absorbed and also radiated back into space. The physical characteristics of Earth’s surface affect how much heat energy is absorbed.

3 Electomagnetic Spectrum: Energy Interactions in Environment
Refracted – bent as pass through Reflected – bounced off Scattered – refracted or reflected in various directions Transmitted – passed through Absorbed – taken into

4 Review of Waves Page 14 of ESRT’s
Wavelength – distance crest to crest (or trough to trough)

5 Reflected Refracted Transmitted

6

7 Solar Energy Color: The darker an object, the more heat it absorbs.
Texture: The rougher an object, the more heat it absorbs. Therefore, dark and rough objects (like rocks) absorb the most heat. Light and smooth objects (like water and snow) do not absorb much at all. Instead, they reflect heat. *****A rougher object will have greater surface area**** (write this down)

8 Which one will get the hottest, the fastest?
Darker color “If this scribbled line were straight” Increased surface area B C A Darker color and increased surface area

9 Click on blue text for animations.

10 Such as: air water and magma
Energy Transfer Energy in the atmosphere and at Earth’s surface is transferred in two main ways: 1. Conduction is the transfer of energy when molecules collide, or actually come in contact with each other. 2. Convection is the transfer of energy through a substance. It is a circular motion!! Warm air rises (due to low density), it then expands and cools (density is now high), so the air then sinks back down. This occurs over and over again. Such as: air water and magma

11 Energy Transfer Think of a pot of boiling water.
Conduction is going on when the flame comes in contact with the pan and heats it up. Then convection occurs within the water itself allowing all the water molecules to heat up and begin to boil.

12

13

14 3. Radiation – heat transfer by electromagnetic waves - no medium needed (can travel through solid, liquid, gas, and space)

15 Temperature Temperature and heat are NOT the same thing!
Heat is an actual energy that’s transferred. Temperature is a measurement of that energy.

16 Temperature As temperature increases, density decreases and vice-versa. As temperature increases, pressure decreases, and vice-versa. Keep these in mind in the next few days, these are VERY important relationships in weather! ESRT ALERT!! – Remember on page 13 you will find a temperature conversion scale that will be very useful!

17 freezes Remember, ice melts and freezes at the same temperature Melts

18

19 Specific Heat The specific heat of a substance is its resistance to heating up or cooling off. If something’s specific heat is high, it takes a long time to heat up, but will keep the heat for a long time.

20 Specific Heat If something’s specific heat is low, it will heat up quickly, but also lose the heat quickly. ESRT ALERT!! – Page 1 contains a chart with the specific heats of some common materials.

21 Look, 3 types of water… Water has a very high specific heat – takes a long time to heat water up, but once it’s warm it stays warm for a long time. Metals, like lead and copper have low specific heats – they will heat up very quickly, but cool down very fast too.

22 Equal masses of lead, granite, basalt, and water at 55° C are exposed to equal quantities of heat energy. Which would be the first to show temperature rise of 10°C? Lead Granite Basalt Water What you need to know!!!!! The larger the specific heat number, the longer it takes to heat up and the longer it takes to cool. Page 1 of ESRT’s Water has a very high specific heat – takes a long time to heat water up, but once it’s warm it stays warm for a long time. Metals, like lead and copper have low specific heats – they will heat up very quickly, but cool down very fast too.

23 What’s going to heat up faster???
Why???

24 Click on blue text for animations.


Download ppt "Energy Energy – ability to do work"

Similar presentations


Ads by Google