Earth is an amazing planet. It has everything that we need: food, shelter, and water. Sure, we need water to drink, but have you thought about using water to create energy? In this experiment, you will demonstrate the power of water by converting the energy in moving water to mechanical energy, which will lift a small weight.
Introduction
About 70 percent of the Earth is covered with ocean water. 98% of the water on Earth is in the ocean and is undrinkable because it is salty. 2% of the water on Earth is freshwater and is drinkable. However, 1.6% of freshwater is frozen in the polar ice caps. But no matter where the water is, it is moving and it is part of the water cycle. The water cycle occurs when water evaporates from bodies of water on Earth, like oceans, and then condenses into clouds. Eventually, the clouds become too heavy and the water returns to Earth in the form of rain or snow, also called precipitation. When the water comes back to Earth, some of it flows back into the ocean. As water moves back to the ocean via rivers or waterfalls, it carries a lot of energy with it. We can harness this energy to make electricity or to power machines. This is called hydropower. Because water is constantly and endlessly moving through the water cycle, hydropower is a renewable form of energy, which means the energy can be obtained over and over through natural processes.
Energy and Power Science Project The water cycle
Figure 1. The water cycle.
Energy and Power Science Project Hungy Horse Dam
Humans have been using hydropower for centuries, harnessing the energy of water. See how falling water can lift a small weight. If just a little flow of water can lift a weight, imagine the amazing energy of the Niagara Falls!
Energy and Power Science Project Niagara Falls
Figure 3. The Niagara Falls.
Terms, Concepts and Questions to Start Background Research
Water cycle
Condensation
Precipitation
Hydropower
Mechanical energy
Energy
Power
Materials and Equipment
Aluminum pie plate, 9 inches; available at all grocery stores
Scissors
Permanent marker
Waterwheel template; use Figure 5 as your model.
Ruler
Nylon spacer, 3/8-inch inner diameter and 3/8 inch thick. The spacer must fit in the center of the waterwheel. These are available at hardware stores. See Figure 7, below, to see what a nylon spacer looks like.
glue;
tape
Wood dowel, 5/16 inch wide and 2 feet long; available at craft stores
Plastic bucket with removable handle, 14 quarts
Cotton string, 30-inch-long piece
Metal nut or other small metal object that string can be tied to
Measuring cup, 2-cup is best
Stopwatch
Lab notebook
Experimental Procedure
Take your scissors and cut out the flat bottom part of the aluminum pie plate.
With the permanent marker, copy the design from the waterwheel template (Figure 5) onto the circle of aluminum. Draw the lines from the edge of the circle to about 2 centimeters (cm) from the middle of the circle.
Energy and Power Science Project Waterwheel template
Energy and Power Science Project
|| Figure 4. Waterwheel template (Courtesy of AFRED, Railroad Commission of Texas). ||
3. Cut the aluminum circle along the eight solid lines. End each cut at 2 cm from the center. These are the paddles of the waterwheel.
4. Carefully bend each paddle at its dotted line. Put the ruler at each dotted line so that you can make a straight bend. See Figure 6.
5. Glue the nylon spacer to the middle of the waterwheel. Ask an adult for help. The nylon spacer stiffens the waterwheel.
Energy and Power Science Project completed waterwheel
|| Figure 5. Here is a completed waterwheel. ||
6. Ater the glue dries, use thin strips of tape to secure the nylon spacer to the waterwheel. Make sure that the hole in the center is not covered with tape.
set the water wheel aside.
7. Remove the handle from the bucket. Make sure that the wood dowel can fit comfortably through the holes and spin freely. It should not be a tight fit.
Science Project
|| Figure 6. The wood dowel fits comfortably through the two drilled holes. ||
8. Wind a piece of tape around the middle of the wood dowel. This is to add some thickness in order to keep the waterwheel in place. Now insert the dowel through the holes of the bucket. Move the dowel out of one of the holes and carefully slip the waterwheel onto the dowel over the piece of tape. Reinsert the dowel through the hole in the bucket. Turn the waterwheel and make sure that the wood dowel turns as well. If the dowel doesn't move, you should gently move the waterwheel off of the tape and wind another piece of tape over the original piece of tape to add thickness so the two objects move at the same time. The waterwheel must sit tightly on the dowel so that when the waterwheel turns, the dowel turns.
Energy and Power Science Project waterwheel apparatus
|| Figure 7. Waterwheel apparatus. ||
9. Take the cotton string and tie one end to the metal nut. Tie the other end of the string to one end of the wood dowel, outside of the bucket. Tie the end such that when the dowel starts to turn, it immediately starts to wind up the string. You need to pay attention to how the waterwheel turns to do this; either clockwise or counterclockwise.
10. Wind some tape and make a little tab (by folding the end of the piece onto itself) on the dowel outside of the bucket on both ends so that the waterwheel and dowel don't move horizontally too much—you don't want the dowel slipping out of the holes. The waterwheel should be sitting in the middle of the bucket and should be able to turn freely, without hitting the bucket. Now you are ready to start converting the kinetic energy in falling water to mechanical energy.
11. To do these experiments you can use any source of moving water, like a sink or bathtub faucet, or an outdoor hose.
Energy and Power Science Project using sink faucet to turn waterwheel
Energy and Power Science Project using garden hose to turn waterwheel
|| Figure 8. Using the sink faucet to turn the waterwheel. || Figure 9. Using the garden hose to turn the waterwheel. ||
12. Using the measuring cup and the stopwatch, first calculate the flow rate of the water source you are using. You will do this by seeing how long it takes to fill 2 cups of water. Note this time down in your lab notebook in a data table like the one below. Divide 2 cups by the number of seconds it took to fill 2 cups. This is the flow rate and its unit of measure is cups per second. Note down the flow rate in your lab notebook. Do not turn off the water between measuring the flow rate and testing the waterwheel or else you will have to redo the flow rate calculation (you might turn the faucet on harder or softer the next time, which would negatively affect your results).
13. Make sure that the string and weight are unwound before you begin. Place the waterwheel under the flowing water. Measure the height of the flowing water with the ruler. Record this information in your lab notebook. Using the stopwatch, time how long it takes to wind the weight up. Note this time in your lab notebook. Repeat this measurement two additional times at the same water height and record the information in your lab notebook. One thing to keep in mind is to not let the bucket get too full of water or else the bucket water will get in the way of the waterwheel. Once you've filled the bucket to the point where the waterwheel won't turn anymore, don't just waste it—you can use this water to water your garden or put it in your dog's water bowl. Note: Make sure that the water hits the waterwheel in the same spot for every trial. The waterwheel should go either clockwise or counterclockwise each time. Record all information in your lab notebook.
14. Now you do want to change the flow rate of your water source, so adjust it and repeat steps 13 and 14. Make sure that the trials are all done at the same water height. Change the flow rate one more time and repeat steps 13 and 14 again. So you should have three trials each for three different flow rates.
15. Does the time it takes to wind the weight change? Can water be used to do work? How does that help the earth?
16. Plot your data on a scatter plot. Plot the flow rate on the x-axis and the wind-up times and the average wind-up time on the y-axis. If you need help making scatter plots you can check out this website: Create a Graph
Water Cycle:
Earth is an amazing planet. It has everything that we need: food, shelter, and water. Sure, we need water to drink, but have you thought about using water to create energy? In this experiment, you will demonstrate the power of water by converting the energy in moving water to mechanical energy, which will lift a small weight.
Introduction
About 70 percent of the Earth is covered with ocean water. 98% of the water on Earth is in the ocean and is undrinkable because it is salty. 2% of the water on Earth is freshwater and is drinkable. However, 1.6% of freshwater is frozen in the polar ice caps. But no matter where the water is, it is moving and it is part of the water cycle. The water cycle occurs when water evaporates from bodies of water on Earth, like oceans, and then condenses into clouds. Eventually, the clouds become too heavy and the water returns to Earth in the form of rain or snow, also called precipitation. When the water comes back to Earth, some of it flows back into the ocean. As water moves back to the ocean via rivers or waterfalls, it carries a lot of energy with it. We can harness this energy to make electricity or to power machines. This is called hydropower. Because water is constantly and endlessly moving through the water cycle, hydropower is a renewable form of energy, which means the energy can be obtained over and over through natural processes.
Humans have been using hydropower for centuries, harnessing the energy of water. See how falling water can lift a small weight. If just a little flow of water can lift a weight, imagine the amazing energy of the Niagara Falls!
Terms, Concepts and Questions to Start Background Research
Water cycle
Condensation
Precipitation
Hydropower
Mechanical energy
Energy
Power
Materials and Equipment
Aluminum pie plate, 9 inches; available at all grocery stores
Scissors
Permanent marker
Waterwheel template; use Figure 5 as your model.
Ruler
Nylon spacer, 3/8-inch inner diameter and 3/8 inch thick. The spacer must fit in the center of the waterwheel. These are available at hardware stores. See Figure 7, below, to see what a nylon spacer looks like.
glue;
tape
Wood dowel, 5/16 inch wide and 2 feet long; available at craft stores
Plastic bucket with removable handle, 14 quarts
Cotton string, 30-inch-long piece
Metal nut or other small metal object that string can be tied to
Measuring cup, 2-cup is best
Stopwatch
Lab notebook
Experimental Procedure
Take your scissors and cut out the flat bottom part of the aluminum pie plate.
With the permanent marker, copy the design from the waterwheel template (Figure 5) onto the circle of aluminum. Draw the lines from the edge of the circle to about 2 centimeters (cm) from the middle of the circle.
|| Figure 4. Waterwheel template (Courtesy of AFRED, Railroad Commission of Texas). ||
3. Cut the aluminum circle along the eight solid lines. End each cut at 2 cm from the center. These are the paddles of the waterwheel.
4. Carefully bend each paddle at its dotted line. Put the ruler at each dotted line so that you can make a straight bend. See Figure 6.
5. Glue the nylon spacer to the middle of the waterwheel. Ask an adult for help. The nylon spacer stiffens the waterwheel.
6. Ater the glue dries, use thin strips of tape to secure the nylon spacer to the waterwheel. Make sure that the hole in the center is not covered with tape.
set the water wheel aside.
7. Remove the handle from the bucket. Make sure that the wood dowel can fit comfortably through the holes and spin freely. It should not be a tight fit.
|| Figure 6. The wood dowel fits comfortably through the two drilled holes. ||
8. Wind a piece of tape around the middle of the wood dowel. This is to add some thickness in order to keep the waterwheel in place. Now insert the dowel through the holes of the bucket. Move the dowel out of one of the holes and carefully slip the waterwheel onto the dowel over the piece of tape. Reinsert the dowel through the hole in the bucket. Turn the waterwheel and make sure that the wood dowel turns as well. If the dowel doesn't move, you should gently move the waterwheel off of the tape and wind another piece of tape over the original piece of tape to add thickness so the two objects move at the same time. The waterwheel must sit tightly on the dowel so that when the waterwheel turns, the dowel turns.
|| Figure 7. Waterwheel apparatus. ||
9. Take the cotton string and tie one end to the metal nut. Tie the other end of the string to one end of the wood dowel, outside of the bucket. Tie the end such that when the dowel starts to turn, it immediately starts to wind up the string. You need to pay attention to how the waterwheel turns to do this; either clockwise or counterclockwise.
10. Wind some tape and make a little tab (by folding the end of the piece onto itself) on the dowel outside of the bucket on both ends so that the waterwheel and dowel don't move horizontally too much—you don't want the dowel slipping out of the holes. The waterwheel should be sitting in the middle of the bucket and should be able to turn freely, without hitting the bucket. Now you are ready to start converting the kinetic energy in falling water to mechanical energy.
11. To do these experiments you can use any source of moving water, like a sink or bathtub faucet, or an outdoor hose.
|| Figure 8. Using the sink faucet to turn the waterwheel. || Figure 9. Using the garden hose to turn the waterwheel. ||
12. Using the measuring cup and the stopwatch, first calculate the flow rate of the water source you are using. You will do this by seeing how long it takes to fill 2 cups of water. Note this time down in your lab notebook in a data table like the one below. Divide 2 cups by the number of seconds it took to fill 2 cups. This is the flow rate and its unit of measure is cups per second. Note down the flow rate in your lab notebook. Do not turn off the water between measuring the flow rate and testing the waterwheel or else you will have to redo the flow rate calculation (you might turn the faucet on harder or softer the next time, which would negatively affect your results).
13. Make sure that the string and weight are unwound before you begin. Place the waterwheel under the flowing water. Measure the height of the flowing water with the ruler. Record this information in your lab notebook. Using the stopwatch, time how long it takes to wind the weight up. Note this time in your lab notebook. Repeat this measurement two additional times at the same water height and record the information in your lab notebook. One thing to keep in mind is to not let the bucket get too full of water or else the bucket water will get in the way of the waterwheel. Once you've filled the bucket to the point where the waterwheel won't turn anymore, don't just waste it—you can use this water to water your garden or put it in your dog's water bowl. Note: Make sure that the water hits the waterwheel in the same spot for every trial. The waterwheel should go either clockwise or counterclockwise each time. Record all information in your lab notebook.
14. Now you do want to change the flow rate of your water source, so adjust it and repeat steps 13 and 14. Make sure that the trials are all done at the same water height. Change the flow rate one more time and repeat steps 13 and 14 again. So you should have three trials each for three different flow rates.
15. Does the time it takes to wind the weight change? Can water be used to do work? How does that help the earth?
16. Plot your data on a scatter plot. Plot the flow rate on the x-axis and the wind-up times and the average wind-up time on the y-axis. If you need help making scatter plots you can check out this website: Create a Graph
Science experiment from the website http://www.sciencebuddies.org/science-fair-projects/project_ideas/Energy_p021.shtml
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