Chapter 2: Recognizing Energy Transfer Objective: recognize that energy moves from place to place and changes forms to make things happen

Energy Transfers The movement of energy The movement of energy –Every time something happens energy is involved –Movement of energy from one object to another, one form to another, and one place to another causes a change

Energy Transfers and the Natural World Energy transfers from the sun Energy transfers from the sun –Earth receives a steady supply of energy from the sun, the source of all weather from the sun, the source of all weather Clouds and Precipitation Clouds and Precipitation –Heats water which evaporates, cools and condenses to form clouds, then falls as precipitation (water cycle) Wind Wind –Sun does not heat the Earth equally  Uneven heating causes wind Storms Storms –Come from transfer of sun’s energy to the Earth  Forms hurricanes- see p. 15

Photosynthesis The transfer of energy from the sun feeds plants The transfer of energy from the sun feeds plants –Almost all living things depend on food created by green plants Have special colored substance that catches the sun’s energy Have special colored substance that catches the sun’s energy –Use this light energy to create food (chemical energy)  Called Photosynthesis  plants use food to grow and when animals eat the plants, the energy transfers to them

Energy Transfers from Inside the Earth Energy also comes from the Earth’s center (4300 C to 7200 C) Energy also comes from the Earth’s center (4300 C to 7200 C) –Causes changes on surface like earthquakes and volcanic eruptions Heat energy from deep in the earth is being transferred to motion energy Heat energy from deep in the earth is being transferred to motion energy

Heat Transfer from Earth’s Core Cause of Earthquakes Cause of Earthquakes –Core- center of the earth is very hot –Heat energy is transferred from core out towards surface out towards surface Heat makes mantle so hot that it can flow slowly Heat makes mantle so hot that it can flow slowly The earth’s crust rests on the mantle The earth’s crust rests on the mantle –As the mantle flows, the crust shifts causing an earthquake Cause of Volcanic Eruption Cause of Volcanic Eruption –Heat from core is transferred to rock under the earth’s surface The rock melts, and sometimes escapes through cracks The rock melts, and sometimes escapes through cracks

Energy Transferred Between Living Things Some energy transfers happen so slowly, or on such a small scale, it is hard to see them at all Some energy transfers happen so slowly, or on such a small scale, it is hard to see them at all –Decomposing log Chemical energy transfers to Chemical energy transfers to living organisms feeding on it living organisms feeding on it –Mushrooms, bacteria, and worms  A large log can take decades

The Food Chain Energy transferred between living things Energy transferred between living things –Food chains show how energy is passed from one organism to another See p. 20 for an example See p. 20 for an example

Frequently Asked Questions Does energy change when it is transferred? Does energy change when it is transferred? –Sometimes it does Sun light (light energy) to plant (chemical energy) Sun light (light energy) to plant (chemical energy) –Sometimes it does not Spoon put in hot liquid Spoon put in hot liquid –Heat travels up through spoon How can I tell that energy is being transferred in the natural world? How can I tell that energy is being transferred in the natural world? –Where ever there is change seasons change, earth changes, living things change seasons change, earth changes, living things change