Download Let`s Convert Energy

Let’s Convert Energy
Point
of Wonder
Have you ever wondered
what forms of energy
surround us each day?
Objective
The students will be introduced to the
different forms of energy and how
energy can change from one form to
another.
Instructional
Information and
Connections
Time: 60 minutes
Curriculum Focus:
language arts, science
Skills/Processes:
conclude, discuss, draw, experiment,
observe
Key Vocabulary:
chemical energy, conversion,
electrical energy, gravitational energy, kinetic energy, mechanical energy, nuclear energy, potential energy,
radiant energy, thermal energy,
wind energy
Careers in Energy:
nuclear engineer
mechanical engineer
chemical engineer
Background
Energy is all around us, all of the time. It may, however, be known by
different names depending on its source. Light, whether it comes from the
sun or a light bulb, is radiant energy. Gravitational energy is the energy
an object has due to its position above the ground. Food and fuel contain
chemical energy, while hot objects contain thermal energy. A machine with
moving parts or a moving fluid has mechanical energy. Charged objects
are filled with electrical energy, and radioactive elements such as uranium
contain nuclear energy.
Another important concept of energy is that it may change forms, or
transform. An electric toothbrush has chemical energy in the battery, which
produces electrical energy, which in turn causes that tooth-scrubbing
motion, mechanical energy for pearly whites.
There are two general types of energy that encompass most of its forms:
potential and kinetic. Potential energy is energy waiting to happen
(gravitational, chemical and nuclear forms are potential); kinetic is energy
in motion (thermal, electrical and mechanical forms are kinetic). That
toothbrush sitting on the counter has the potential energy to clean your
teeth. Once the switch is turned on, that energy is in motion, or kinetic
energy.
Materials / Preparation
• Match and candle
• Electric kettle or hot plate and pan
• Flashlight and batteries
• Shallow box (like a shoe box lid) lined with black plastic, and covered
with plastic wrap that has a hole punched in each end
• Adhesive tape to hold plastic wrap in place
• Plastic bag and twist ties, or zip lock bags, baking soda, vinegar
• Yard (meter) stick or board, balls or other objects that roll
• Rock collection and geiger counter (if available)
• “Draw, Describe, Decide Worksheet” for each student
©2013 National Energy Foundation
Learning Activity
1. Set up each experiment to show the different forms of energy either as a teacher demonstration or a hands-on
experiment, depending on the safety of the materials.
2. Discuss and list the different forms of energy and give examples (as in the Background information).
3. Do the experiments below and have the students fill out their “Draw, Describe, Decide Worksheet.”
A.Light the match. The mechanical energy of striking produces thermal energy from friction, which results
in the release of chemical energy producing heat and light. Now light the candle, transferring thermal
energy from the burning match to the wick and wax, releasing their chemical energy as heat (thermal
energy) and light (radiant energy).
B. Using the kettle, heat a small amount of water to boiling. Have the students observe and document the
energy path from the hot plate’s electrical energy which produces thermal energy, which then transfers to
the water and produces mechanical energy, or the motion of the boiling water.
C. D
emonstrate the flashlight without the batteries and again with the batteries. Help the students understand
the energy conversions from the chemical energy of the batteries to the electrical energy that heats
(thermal energy) the bulb filament and produces light (radiant energy).
D. P lace the prepared shallow box in a sunny windowsill with one hole up. Have the students place their
hand over the top hole. What happens? The sunlight (radiant energy) is absorbed by the black lining and
turns to heat (thermal energy) which is trapped by the plastic wrap. As the air heats up and expands, it
is pushed out the top by cooler, denser air entering at the bottom. (Explain to the students that this is a
good illustration of how wind is produced by heating of the earth’s surface.)
E.In one corner of a plastic bag, place a spoonful of baking soda and seal off the corner with a twist tie.
Then pour in about 50 mL (about 1/4 cup) vinegar, squeeze the air out and seal the bag (use another
twist tie or a zip lock bag). Take off the first tie and let the two chemicals mix. Note the signs of a
chemical reaction: production of gas bubbles which inflate the bag and a change in temperature drop
inside the bag. This reaction takes in heat and releases chemical energy.
F. E
levate one end of a board or meter stick. Roll a ball down
the board to demonstrate gravitational energy. Let the students
experiment with the mechanical energy applied at the top, the
weight of rolling objects, and the ability to knock over objects
at the bottom. The concept would be fun to illustrate using a
playground slide or teeter-totter.
G.If you have access to a geiger counter, test a rock collection,
wrist watches (some contain radium), and a few other materials
to demonstrate nuclear energy radiating from these materials.
4. Discuss the observations and the results of the “Draw, Describe,
Decide Worksheet.”
©2013 National Energy Foundation
Check for Understanding
Have the students draw an energy conversion including three forms of energy (e.g., electrical energy used to produce thermal energy, which toasts a piece of bread, giving chemical energy to the consumer—the person who eats
the toast).
Have students record two or three examples of each form of energy they have seen or used during their experiments today.
To Know and Do More
Make a list of examples of potential (energy waiting to happen) and kinetic (energy in motion) energy.
Potential
a truck at a stoplight
water behind a dam
a skier standing still
a piece of wood
Kinetic
a
a
a
a
truck moving down the road
running river
skier racing down the hill
piece of wood burning
Have a three-minute challenge to see who can come up with the most examples.
Have students research the terms chemical reaction, exothermic and endothermic. Which experiments contained
chemical reactions? (burning the match, using the battery, and the baking soda and vinegar) Which were endothermic? (baking soda and vinegar) Exothermic? (burning, reaction inside the battery)
Career Awareness Activity
Have students research the career of a physicist. What education is required? What is their general area of interest? What is the pay scale? Can a physicist specialize in a particular field or area?
©2013 National Energy Foundation
Draw, Describe, Decide Worksheet
Fill in each column as the experiments or demonstrations are completed.
Sketch the experiment
Describe what happened
Decide the energy forms involved
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D. ________________________________________________________________________________________________________
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E.________________________________________________________________________________________________________
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G. ________________________________________________________________________________________________________
©2013 National Energy Foundation