Make Up Lesson Energy

Energy Transfer

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Objective 1

• Objective 1: Conduction, Convection and Radiation

• You need to know these 3 vocabulary words. I will explain them in the next few slides.

Conduction

• Conduction is when heat is transferred between two objects that are touching each other.

• Think about how WE are conductors of heat. When we touch someone's hand we might transfer some of our heat to them.

• You will see conduction in the real world when:

• Cooking by conduction: The burner on the stove will conduct heat energy to the bottom of a pan on top of it.

• OR The heat from the handle of the pan is transferred to your hand when you touch it.

Here is a picture of conduction in the kitchen.

Convection

• The transfer of thermal (heat) energy by the circulation (the arrows) or movement of a liquid or gas: convection currents Hot liquid/air rises then cools as it falls.

• Just like we talked about how inside of the Earth there are convection currents that move the hot and cold air.

• Anytime you see arrows going in a circular motion this is going to be convection.

Radiation

• When heat is transferred between two objects that are not touching, and can be far apart. Heat transfer by electromagnetic waves.

• Remember: this time the objects are not touching and can be very far apart.

• It is also invisible: So for an example if you are sitting next to a fire you can not see the transfer of heat but you can feel it.

• Things in the world that use radiation to heat are:

• The sun, microwaves, television, burners, bonfire, medical imaging, stereos, ovens, phones.

Multiple Choice

Land heats up during the day by absorbing energy from the sun. The land heats up the air and then the warm air begins to rise and is now currents of cooler air. What type of heat transfer is this? Hint: this is all a circle.

• Radiation

• Conduction

• Convection

Multiple Choice

If you are heating something on the stove and the metal handle becomes hot over time what type of energy transfer causes the handle to be hot.

• Convection

• Conduction

• Radiation

Multiple Choice

If you are holding a candle and it is lit you can feel the heat. The heat travel's to your hands by -

• Radiation

• Conduction

• Convection

Objective 2

• Patterns of thermal energy

• Remember: heat always moves from a warmer to a colder place.

Scenarios

• Objective 2 is about the patterns that thermal energy follow.

• Below are some scenarios, you need to tell what will happen.

Multiple Choice

What would happen if you left a metal spoon in a cup of hot tea?

• the heat from the tea would travel to the spoon until the spoon is the same temperature as the tea

• nothing will happen

• the cold from the metal spoon will travel to the hot tea.

Multiple Choice

Which is an example of thermal conduction?

• the water in the pot absorbs heat

• the pot gets hot from the contact of the stove

• you can feel the heat from the burner.

• water boils because of the currents.

Multiple Choice

Objects that allow heat to transfer easily are known as -

• conductors

• insulators

• radiators

• energy savors

Multiple Choice

If you don't add heat what will happen to an object?

• It will stay hot.

• It will become solid

• it will cool down to room temperature

• it will melt.

Multiple Choice

Heat always goes from -

• Higher to lower temperatures

• Lower to higher temperatures

• it doesn't go anywhere

Energy Transfer and Energy Pyramids

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What is an energy pyramid? Ecological Pyramid is not the same.....

• Ecological pyramids are visual representations of energy flow, biomass accumulation, and number of individuals at different trophic levels.

• The energy pyramid is used in energy transfer from one organism to another along the food chain. The energy decreases as you move from the bottom to the top of the energy pyramid.

Multiple Choice

In an energy pyramid, The energy increases as you move from the bottom to the top of the energy pyramid.

• True

• False

10% Rule

90% of the energy entering each step of the pyramid is used up by the consumers, only 10% of the energy get stored. So, when the next level on the pyramid eats them, that 10% gets passed down to them.

Multiple Choice

If there are 50,000 Joules of Energy available at the producers level, how much will available in secondary consumer trophic level?

• 5000 Joules

• 5 Joules

• 50 Joules

• 500 Joules

Food Chain

The food chain describes who eats whom in the wild. Every living thing—from one-celled algae to giant blue whales—needs food to survive. Each food chain is a possible pathway that energy and nutrients can follow through the ecosystem.

For example, grass produces its own food from sunlight. A rabbit eats the grass. A fox eats the rabbit.

Multiple Choice

A mosquito larva eats the algae, therefore the mosquito larva is a

• primary consumer

• producer

• secondary consumer

• autotroph

• tertiary consumer

Food Web

Different habitats and ecosystems provide many possible food chains that make up a food web.

In a grassland ecosystem, a grasshopper might eat grass, a producer. The grasshopper might get eaten by a rat, which in turn is consumed by a snake. Finally, a hawk—an apex predator—swoops down and snatches up the snake.

Multiple Choice

A scorpion eats grasshoppers and the grasshopper eats plants. What is the scorpion?

• producer

• primary consumer

• secondary consumer

• tertiary consumer