Energy Transformations. Magnetic Field- a region of space near a magnet, electric current, or moving...
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Energy Transformations
Energy Transformations. Magnetic Field- a region of space near a magnet, electric current, or moving charged particle in which a magnetic force acts on
Magnetic Field- a region of space near a magnet, electric
current, or moving charged particle in which a magnetic force acts
on any other magnet, electric current, or moving charged particle.
Insulator-A material that blocks the flow of electric current
across it. Energy- The ability to do work Work- applying a force to
an object over a distance, and (2) the object moves in response to
the force. Newtons-SI units used to measure force.
Slide 3
2.Stored energy is chemical energy. 3.Heat outside is generated
by solar energy. 4.If the particles in an object slow down, that
means the temperature is cool or cold. 5.Form of energy in a
battery is chemical energy. 6.How do I tell which car has the most
kinetic energy? The one that is moving the fastest.
Slide 4
7.What is the energy transformation when a stretched rubber
band is released? Potential energy transformed to kinetic energy.
8.What does the Law of Conservation of energy sat is true of all
energy transformations? That energy is never created or destroyed
and the sum of all the energies is constant.
Slide 5
9.When you move your leg, your body changes chemical energy
supplied by food into mechanical kinetic energy. 10. When wood
burns, chemical energy stored in the wood is changed into heat
energy, and light energy. 11. Water flowing over a water fall is a
good example of kinetic energy.
Slide 6
12.Describe the energy transformation in an electric motor.
Chemical energy transforms to electrical energy to mechanical
energy. 13. If you wrap an electrical wire around an iron core, you
create a electromagnet 14. An electric motor transforms electrical
energy into mechanical energy. 15. How do you increase the strength
of an electromagnet? Increase the number of times you wrap the wire
around the iron core
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16.What does a generator do? Converts mechanical energy to
electrical energy. 17. What energy transformations occur when a
hair dryer is plugged into the outlet? Electrical energy is
converted to heat energy. 18. Describe the energy transformations
in an electric fan. Electric energy to kinetic energy.
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19. Energy Transformations a.Light bulb is electrical to light
energy and heat energy. b.Door bell is electrical to sound energy.
c.Stove is electrical to heat energy. d.Fan is electrical to
mechanical
Slide 9
20. Describe the way heat moves. Heat moves in three ways:
Radiation, conduction, and convection. Radiation happens when heat
moves as energy waves, called infrared waves, directly from its
source to something else. Conduction is another way that heat moves
through contact. Convection happens when a substance that can flow,
like water or air is heated.
Slide 10
21.Infrared heat lamps are used at fast food restaurants to
keep food hot. How is heat transferred to the food? Radiation.
22.The water at the top of a pot of water gets hot by convection.
23.A cool metal spoon gets hot while sitting in your moms coffee.
How does this happen? By conduction.
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23. Explain how a metal spoon gets hotter than a plastic spoon.
Metal is a better conductor of heat than plastic. Plastic is an
insulator. 24. Same as above. 25. True or false? A student lifting
her books off the table is an example of work. True.
Slide 12
26.What instrument can be used to measure force? Spring scale.
27. How do simple machines make work easier for you? Simple
machines reduce the amount of force needed to do the work. 28. How
can you adjust a lever to lift a heavy box? Move the fulcrum closer
to the load. 29. How can you adjust a ramp to push a heavy object
up the ramp? Make the ramp longer.
Slide 13
30.How do you adjust a pulley system to require the least
amount of effort to lift a weight? Add more pulleys. Or add a
moveable pulley. 31. What simple machine is found in raising
blinds, lifting a car with a construction crane, and using a block
and tackle? Pulley 32.Which of the following is not considered a
simple machine?
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33.A pair of scissors is made of wedge and lever. 34.A door
knob is made of which simple machine? Wheel and axle 35.Of the
following, which is an example of a complex machine? Can
opener.
Slide 15
Slide 16
Focus Question: How can you make a magnet that turns on and
off? Challenge: Can you make a steel bolt into a magnet that will
turn on and off? Test the rivet for magnetism by trying to move the
washers. Materials 1 steel bolt 1 electromagnet wire (very long
wire) 3 wires 1 compass 1 battery 1 switch 1 cup of paper clips
Electromagnets Activity 3.3
Slide 17
Share with the class: How did your group make a magnet that
could turn off and on?
Slide 18
You need to know An electromagnet is a piece of iron or steel
with insulated wire wrapped around it. While electric current is
flowing through the wire, the iron or steel becomes a temporary
magnet.
Slide 19
1.What caused the electromagnet to become magnetic? 2.What
happens when the switch is opened? 3.What happens when the battery
is reversed or the wire connections are reversed? Electromagnets
Activity 3.3
Slide 20
You need to know To make an electromagnet stronger, you could
Increase the number of coils of insulated wire around the iron core
Or Use more batteries or a battery with greater voltage in the
electric circuit Or Increase the diameter of the core (use a
thicker nail or rivet!)
Slide 21
Electromagnets Electromagnets: Using Electricity and Magnets
Together A Segment of: A First Look: Magnets (1:42)A First Look:
Magnets
Slide 22
Motors An electromagnet is a very important part of a motor. A
motor changes electric energy to mechanical energy!
Slide 23
Focus Question: How does an electric motor transform electric
energy to mechanical energy? Follow the first and second student
procedures outlined on page 43 of your Team Handbook Explore
Electric Motors Activity 3.4
Slide 24
Click on picture above for link with animations of a motor An
electric motor contains an electromagnet that rotates between the
poles of a permanent magnet. The coil of the electromagnet is
connected to a battery or other source of electric current. When
the current from the battery flows through the wire in the
electromagnet it produces a magnetic field and becomes a magnet.
Like poles of the magnets repel and unlike poles of the magnets
attract. This causes the coil to rotate and thus changes electrical
energy to mechanical energy! electromagnet Permanent magnet
battery
Slide 25
What are electric motors? An electric motor is a device which
changes electrical energy into mechanical energy.
Slide 26
Go to the next slide How does an electric motor work?
Slide 27
Simple as that!!
Slide 28
Apply Making a Motor Activity 3.4 Follow instructions on page
46 of Team Handout. Pictures for some of the steps are shown in the
following slides!
Slide 29
Step 2
Slide 30
Step 3 These 2 wires are NOT touching each other!
Slide 31
Step 4 These wires are still not touching!
Slide 32
Step 6
Slide 33
Step 7: Watch the motor turn!
Slide 34
We have seen how electricity can produce a magnetic field, but
a magnetic field can also produce electricity! Moving a loop of
wire through a magnetic field produces an electric current. A
generator is used to convert mechanical energy into electrical
energy.
Slide 35
Slide 36
Generating Electricity at a Power Plant A Segment of:
Electricity and Magnetism: Generating ElectricityElectricity and
Magnetism: Generating Electricity