Focus Question: How does the Sun Heat Up the Earth?

Investigation 4-1

Energy Observed evaporation

– Liquid water turned to gas (water vapor), and went into the air

Water is evaporating all over Earth Change from liquid water to gas

requires energy. – Where does the energy to evaporate all

that water come from? Energy from the Sun, solar energy,

provides energy to change liquid water into water vapor.

Earth Materials Nonliving substances that make up or

come from Earth. Examples? Observe soil and water samples -

– What will happen when these earth materials are placed in the Sun?

– Will the temperature change be the same in both materials?

– What will happen when they are placed in the shade?

Investigation Materials Let’s set up an experiment to find out

how solar energy heats the two earth materials.

Equipment: – Container with slotted lid– 50ml syringe– 100ml beaker

Design experiment– Key pieces?

Experimental Plan - Heating Earth Materials A and B

Question - clearly/precisely describes what you expect to find out by doing experiment

Materials - complete list of items and quantities of items needed to conduct experiment

Experimental Plan - Heating Earth Materials A and B

Procedure elements - – Equal volumes of each material in two containers

(100ml)– Record starting temperature– Place both containers in the sun. Record

temperatures at regular intervals (3 min) for 15 minute period

– Move containers to shade. Continue recording temperatures at same intervals for equal period of time

Experimental Plan - Heating Earth Materials A and B

Data table - – Set up T-table with 3 columns

Time (independent variable) Water temperature (dependent variable 1) Soil temperature (dependent variable 2)

Discuss and write experimental procedure, set up data table

Experiment Set-up Thermometer set-up

– Position thermometer under the lid at the slit

– Gently slide thermometer up through the slit

– Put lid on container. Adjust the thermometer so bulb is under the surface of the earth material

Set up experiment - use 100ml of water and 100ml of dry soil

Cardboard Surface

Conducting experiment to find out what happens to soil and water when they are place in sunshine. Don’t want heat from the ground to affect results.

Use a piece of cardboard to keep heat from entering system from the ground.

Equalize temperatures tonight - Monday you’ll set up on cardboard.

Store set-up with sticky note label.

Graph and Analyze Results Create temperature vs. time line

graphs for both water and soil. Use different colored pencils and labels to identify the two graphs.

When you are finished graphing, answer the questions at the bottom of the page.

Graph

Graph Discussion What was the dependent variable in

this experiment? What variables did you control? Which material heated up more in the

sun? How many degrees did the dry soil

heat up while it was in the sun? How many degrees did the water heat

up while it was in the sun? What happened to the soil and water

when they were moved to the shade? Which material heated up and cooled

down faster?

Energy Transfer Sunshine is solar energy.

– Solar energy comes to Earth in the form of light.

– Solar energy travels through space and through Earth’s air, hits the earth materials in the containers, and heats them up.

Process is called Energy Transfer.– Light energy from the sun is absorbed by

the water and soil. – When solar energy transfers to soil and

water, the water and soil get heated.

Solar Exposure Solar-energy exposure is the amount of

sunshine that falls on an object.– Solar-energy exposure depends on the intensity

(brightness) of the light and the length of time it falls on the object.

Which earth material was exposed to more solar energy?

Why do you think the soil got so much hotter than the water?

Heat Sink Water has an interesting property.

– Takes 5 times more energy to raise water 1 degree than it takes to raise dry soil 1 degree.

If both soil and water are exposed equally to solar energy, soil will heat up faster than water.

Energy is absorbed by water– Temperature does not go up as fast as

when soil absorbs same amount of energy– Takes longer for water to heat up AND to

cool down

Heat Sink Any material that can absorb heat is

called a heat sink.– Water is a very good heat sink - it can

hold a lot of heat.– Soil is not a good heat sink - it heats up

and cools down quickly

Vocabulary Earth Material

– nonliving substance that makes up or comes from the earth

Solar Energy– energy from the Sun. Forms of solar energy

include visible light and infrared light that can be felt as heat.

Energy Transfer– change of energy from one form to another (ie.

light to heat), or movement of energy from one object to another (ie. heat moving from air to water).

Heat Sink– a material (ie. water) that can absorb a large

amount of heat.

Concepts What happens to materials exposed to

solar energy? Do soil and water heat up at the same

rate? Your questions? Homework - Read Uneven Heating

pg. 198-201 and answer questions.

Uneven Heating What causes Earth’s surface to heat

up? What are some of the variables that

cause uneven heating of Earth’s surface?

What happens to the temperature of equal volumes of dry soil and water when they are placed in the sunshine for 30 minutes?