Download Science Unit 5 Powerpoint 2 Energy

Science Focus Lesson
Transformation of
Electrical Energy
Objective: I will be able to investigate and explain
that electrical energy can be transformed into
heat, light, and sound energy, as well as the energy
of motion.
Essential Question:
How can electrical energy be transformed into other
forms of energy?
Vocabulary:
electrical energy
closed circuit
transform
attract
conductor
repel
insulator
Electricity is a form of energy that is produced when
electrons move from one place to another place.
Electrical Energy can be transformed or changed into heat,
light, and sound energy.
Heat
Sound
Light
Attract means to pull on
Repel means to push against
+
+
_
_
Like charges repel each other.
+
_
Unlike charges attract each other.
An electrically charged object can attract an
uncharged object and/or either attract or repel
another charged object without any contact
between the objects.
Attraction
Attraction
Repulsion/Repel
Partner A: Tell your shoulder partner what
3 ways electrical energy can be
transformed and give an example of each.
Partner B: Tell your shoulder partner
the difference between attract and
repel and then tell what happens to
like charges and what happens to unlike
charges.
Electric current flows through a path called a
circuit. A circuit is like a big loop. In order for
the current to flow through the loop, the path
must have no breaks; in other words, it must
be closed. A closed circuit has no breaks in
it. An open circuit has a break.
Closed circuit – Light bulb is on
Open circuit – Light bulb is off
Anything that allows heat/thermal energy or electricity to
move through it easily is a conductor.
Anything that slows the movement of heat/thermal energy or
electricity is an insulator.
Take a look at the picture:
The cookie sheet is a conductor. Metals
are good conductors of heat/thermal
energy and electricity.
The oven mitt the mom is wearing is an
insulator. Thick fabrics, plastics, and rubber
are not good conductors of heat/thermal
energy and electricity.
Heat is the transfer of thermal energy between
objects of different temperatures.
Heat travels from a warmer object to a cooler object. The
heat will continue to flow until the temperature of the two
objects has equalized, or reached the same temperature.
For example, suppose you place an ice
cube in a glass of water. Because the
water is warmer than the ice, heat flows
from the water to the ice until the two
reach the same temperature. Heat does
not flow from the ice to the water.
Energy from the sun can be used to heat
objects.
Solar energy mostly passes through the atmosphere and this heat
is absorbed by all objects, such as humans, trees, flowers, roads,
etc. These objects will then warm up. Dark objects, such as asphalt
roads, will absorb and warm faster than light colored objects.
When sunlight is not present, heat may be lost.
With your shoulder partner, have a discussion about the
following:
Discuss the difference between open and
closed circuits.
Discuss conductors and insulators and give
examples
Discuss what you have learned about the flow of heat
Guided Practice
Work with your shoulder partner to answer each question
1.
Benny’s family bought a new electric stove. The
stovetop had several large circles on it. When
Benny’s father turned on the stove, the circles glowed
with a red color. What can you infer about these
circles?
A. The circles gave off both heat and light.
B. The circles gave off only light to show where to place
the pans.
C. The circles gave off light but not heat.
D. The circles gave off light to help the cook see the
stove.
The circles gave off
both heat and light.
Guided Practice
2. It was a hot, sunny day. Marsha’s family was at the
beach. Marsha took off her sandals and headed for the
water. The sand was so hot, she had to run so her feet
would not burn. Which of the following best explains
why the sand was so hot?
A. People running in the sand made the sand hot.
B. Heat and light from the Sun made the sand hot.
C. Wind blowing over the sand made the sand hot.
D. The temperature that day made the sand hot.
Heat and light from
the Sun made the
sand hot.
Guided Practice
3. Alex turned on the light in his room so he could do his
homework. What type of energy transformation is
taking place in Alex’s room?
A. electrical to light
B. light to mechanical
C. mechanical to heat
D. heat to electrical
Electrical to Light
With your shoulder partner, find some
sources of electrical energy in your
classroom. Name the sources you find
and what form of energy it creates. If
time, share with the class.
Check Your Understanding
Record your answers. Check them at the end.
1.
The electric meter at Karen’s house measures the
amount of electricity her family uses each month.
Last month, her family installed a solar water heater.
They no longer use electricity to heat their water.
Which of the following can Karen’s family predict?
A. Their water bill will go up.
B. Their electric bill will go up.
C. Their electric bill will go down.
D. Their water bill will go down.
Check Your Understanding
2. Which picture shows a closed circuit?
A.
B.
Check Your Understanding
3. Which of the following items would be the BEST
conductor of heat?
A.
B.
C.
D.
A plastic spoon
An oven mitt
A wooden board
A metal pan
Check Your Understanding
4. If you added ice cubes to a glass of water, which of the
following would happen?
A. The heat from the glass would flow to the ice.
B. The heat from the ice would flow to the water.
C. The heat from the air outside the glass would flow to the
water.
D. The heat from the water would flow to the ice.
Check Your Answers
1. C
2. A
3. D
4. D
Write a summary paragraph explaining your
understanding of one of the following:
*How electricity transforms into other forms of
energy
*The difference between conductors and
insulators
*The flow of heat
*The difference between open and closed
circuits