Download Lab 2: Hydro and Mechanical Energy Transfer

LAB 2: HYDRO AND MECHANICAL ENERGY TRANSFER
Lab 2: Hydro and
Mechanical Energy Transfer
Materials Needed:
Hand Crank
Multimeter
Alligator clips
DC buzzers and bulbs
Hydropower water wheel
Engaging Activity
Demonstrate Hydropower in classroom sink. If necessary, use a few gallons of water outside with a plastic
tub. Allow students to see the difference between a large and small water flow. Connect a multimeter to the
generator and ask students to explain what they see. How and why is energy being created? Ask students to
follow the flow of energy with you.
Water falls due to gravity (potential energy), and flows (kinetic energy), rotates the water wheel (mechanical
energy), rotates the magnets in the turning generator (mechanical energy), magnetic field causes electricity
(electrical energy), we can read this voltage on the multimeter.
Transfer of Energy: Potential to Kinetic to Mechanical to Electrical to Light Energy!
Ask students about other objects that a river or waterfall could power. Have students explain the kind of
energy transfer that would happen. For example, a TV (sound and light energy), a radio (sound energy), a
blender (mechanical and sound). Heat is also lost in each transfer of energy. A student might notice that a TV
or iPad gets hot over time. Heat loss is energy being transferred into heat. Engineers try to limit heat loss,
but sometimes it’s helpful, for example a grill transfers electrical energy to heat energy. Energy is not created
or destroyed, it is transferred. Even when we say heat is “lost”, it is not disappearing, but being transferred to
a different form of energy. The energy flow game simulation website is a good activity to demonstrate energy
transfer.
Explain that students will now transfer the stored energy in their bodies, called chemical energy to another
kind of energy. Ask students how they received their chemical energy (from food calories)! Distribute hand
crank generators, multimeters, alligator clips, and buzzers to teams of students. Before attaching anything
new to the cranks, allow students a few minutes to manipulate the materials, then ask students what kinds of
energy they observed. Organize this information at the board to help students draw a flow chart, which may
look like the chart below.
Me
Turn hand crank
Generator rotates
Bulb lights up
Buzzer makes sound
or…
Chemical energy
from calories
Mechanical energy
Electrical energy
Light energy
Sound energy
Explain that students will experiment with electrical energy by transferring it from their own chemical energy.
Electrical energy will be measured in volts for this lab. Students need to gather data on how much voltage is
needed to turn on a light vs. how much is needed to turn on a buzzer. Have student hypothesize which device
will need more energy transfer, the bulb or the buzzer.
ENERGY TRANSFER
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LAB 2: HYDRO AND MECHANICAL ENERGY TRANSFER
Lab 2: Hydro and
Mechanical Energy Transfer
Name: ______________________________________Date: ____________________________
Background:
Draw a flow chart to show the energy transfer in this lab.
Hypothesis:
If energy is transferred into either a buzzer or bulb then the buzzer will need
(circle) more or less energy to work than the bulb.
Method:
1. _____________________________________________________________________________________
2. _____________________________________________________________________________________
3. _____________________________________________________________________________________
Data:
Voltage
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Buzzer
Is there Sound?
I S L A N D E N E R G Y I N Q U I R Y
Voltage
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Bulb
Is there Light?
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LAB 2: HYDRO AND MECHANICAL ENERGY TRANSFER
Lab 2: Hydro and
Mechanical Energy Transfer
Results:
Using your data, color in the number lines.
1) Voltages that turn on the light.
0 volt
1 volt
2 volt
3 volt
4 volt
1 volt
2 volt
3 volt
4 volt
2) Voltages that turn on the buzzer.
0 volt
Conclusion:
Use greater than, less than, or equals to explain which needed more energy. Buzzer
Did your results agree with your hypothesis? (Circle)
Yes, supported!
Bulb
No, not supported!
Explain why you decided to circle yes or no.
______________________________________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________
ENERGY TRANSFER
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LAB 2: HYDRO AND MECHANICAL ENERGY TRANSFER
Lab 2: Hydro and
Mechanical Energy Transfer
Extensions
With the hand cranks, students can keep track of revolutions. Students could measure how many
revolutions per minute are needed to keep a light on or turn on a buzzer. Students could also
collect data on revolutions per minute and voltage using the multi-meters. An interesting line
graph would be to plot Voltage vs. Revolutions to show a relationship between mechanical and
electrical energy!
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I S L A N D E N E R G Y I N Q U I R Y
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