Water Wheel Lab

Water Wheel Work, Power, and Efficiency

Pre-Lab Preparation:

Purpose: The purpose of this lab was to create an efficient water wheel that would produce a productive time in lifting the cup of nuts and bolts that was attached to the pipe used in rotating out water wheel. The more efficient our wheel was the better the time we would have in lifting our cup. We were then able to observe the work that was needed to turn the axel, the time that is taken to bring the cup of washers to the axel, and the power it took to do all of this. We used our observation, constructing, and testing skills in order to come up with an efficient way to build a water wheel.

Hypothesis: If we successfully created an energy conversant (efficient) water wheel using household items, then we will be able to lift a cup of washers in a very efficient time.

Materials:
• Two gallon paint bucket
• Small pipe to act as your pivot point
• Two paper plates
• Small paper cups
• Duck tape
• Scissors
• Meter stick
• Stop Watch
• Small nuts and bolts
• String

Pre-Lab Questions:
1. State the formula for work. What is the unit it is measured in?
a. W=fd, measured in Joules
2. State the formula for power. What is it measured in?
a. P=w/t, measured in Watts
3. What is the formula for efficiency?
a. Work output/work input X 100= efficiency in a percentage
Procedures and Observations:

Procedures: Observations:
1. Build a water wheel using the materials given and be sure that the wheel will be able to fit within the circumference of the bucket. Make adjustments if needed.
2. Once your wheel is built, measure the radius of the water wheel from the highest point to the axis and record this in the Data Table. Now, assemble your bucket and pipe as the axis to your wheel. Our teacher was kind enough to have already cut out a slot for our axis to sit inside the bucket. See Data Table attached
3. Attach your axis through the center of your water wheel and make sure the axis fits snuggly through the wheel so that when you spin your water wheel the axis moves with it.
4. Fill one small cup with washers and nuts and be sure to measure the mass of the cup with the washers and nuts in grams and record this in your Data Table. See Data Table attached
5. Punch a whole in your cup and attach a string to one end of the axis and the other to the cup. Be sure that the string in securely attached to the axis or it will not properly elevate.
6. Measure the distance from the top of the cup when placed on the ground, to the bottom of your axis directly above the cup. Record this in the Data Table. See Data Table attached
7. Now it is time to conduct the experiment. Fill a two liter bottle with water and measure its mass in kilograms. Record this in the Data Table. See Data Table attached
8. Slowly begin pouring the water onto your water wheel while someone else begins timing. The moment the cup hits the bottom of the axis, stop the clock and go measure the mass of the bottle of water again. Record these findings in the Data Table. See Data Table attached
9. Repeat the previous step at least three times to obtain successful trial times.
10. Use the work out and the times for each trial to calculate the power. Record in the Data Table. See Data Table attached
11. Calculate the efficiency for each trial. What trial was the most efficient and what factors do you think contributed to making this trial most efficient? Trial two was most efficient. Even though it took a greater amount of time, the least amount of water was used during this trial. This resulted in the least amount of work applied to the water wheel, giving the best efficiency.
12. Once all information is obtained, wipe out the bucket and return all materials to its proper place.

Data and Sketches:

Analysis of Experiment and Conclusion:

The graph below is a depiction of our results for the experiment. In blue you will find the time for each trial, red is the power for each, and yellow is the efficiency. Notice that Trial Two had the highest efficiency. Water Wheel Results

Error Analysis:

While conducting our experiment, we did make a few errors. The first error that was observed came when attaching the string from our cup to our axis. The first attempt at our experiment, the string was not securely attached to the axis. Therefore, when we began to pour the water into our wheel, the axis was not lifting the cup. To prevent this next time, we need to be sure that our string is secured tightly.

One other error we encountered during our experimentation was during the testing of our water wheel. The cups that we had attached to the paper plate were sticking out slightly too far and brought challenges when the wheel was spinning within the bucket. One minor adjustment and the problem was fixed. However, next time we could be sure to measure the circumference of the bucket and also the circumference of the plate with the cups attached to be certain there will be no interferences.

Conclusion:

The purpose of this lab was to allow us to build and test our very own water wheel in order to be able to observe the work that was needed to turn the axel, the time is took to bring the cup of washers to the axel, and the power it took to do all of this. We used our observation, constructing, and testing skills in order to come up with an efficient way to build a water wheel. By using some household items such as paper plates, paper cups, and duck tape we were able to construct a fairly efficient water wheel that in the end produced satisfying results. Though we encountered a few minor errors, nothing major happened to alter our results. After conducting our four trials, we found that trial one (See Data Table attached) was the most efficient. Why was this trial the most efficient? When we look at the amount of time it took, you would not think that this trial would have been most efficient. However, when we look further into the details of that trial, we can see that this trial used to least amount of water in creating a force to lift the cup to the axel. This then would result in the best efficiency for all four trials conducted. In comparison to our hypothesis, our results were very close. We hypothesized that is we could create an efficient water wheel; the resulting times it would take to lift the cup of washers would be very efficient. We were able to create a water wheel that did this very thing. Resulting, the most efficiency percentage our wheel produced came in at 32.88%. Overall, in this experiment we successfully constructed an energy efficient water wheel that produced an approximate 33% efficiency rate in lifting our small cup of washers. We were able to use many of the things we have been learning in class and apply them to this very experiment. By the use of this knowledge we were able to observe the changes that took place within the power and efficiency of our water wheel, and by this were able to see the most efficient trial.