address

pwsgarden.blogspot.com

Stream Draft

For the stream chapter of your book you should be reporting on the process, the results, the class results and our overall findings.
Things to consider for the process of collecting data/the data we were collecting:

• length of the section
• width of the section in multiple locations
• depth of the water flow in multiple locations
• Surface Velocity in m/s
• Volume:  We used the length x avg width x avg depth to get the volume.  Assuming all of your measurements were in meters your units will be cubic meters.  Remember that one meter = 3.28 feet.  Be careful to consider if your measurements were in tenths of feet (long orange cased tape) or feet and inches (meter stick, small measuring tape)
• Drop:  We used a water level to measure the change in elevation between the top of your section and the bottom of the section.  By measuring the distance between the water level in the tube and the surface of the water at two locations, then finding the difference between those measurements, you have measured how far the surface of the stream has dropped.
• Flow:  We used our volume measure and our surface velocity to get a measurement of flow in cubic meters per second.  
• Bigger questions to consider, perhaps using the group data:
• Why is surface velocity a flawed measure of flow?
• How are surface velocity and depth related?
• How are surface velocity and drop related?
• Why is flow in cubic meters per second the most accurate picture of the stream?  Explain how it is so that while surface velocity can differ from section to section that flow is constant.
• What are possible sources of error in our data?
• Also consider the process of mapping:
• How did you come up with the scale?
• What was the purpose of the guideline?
• What other techniques did you use?

More tomorrow, but that should keep you busy.  Feel free to post comments, etc.

Mr. H

HW

Inches to cm

Ft to meters

Volume calculation

Launcher Materials

Launch 2

Launch

Bottle Rocket Draft

Your Bottle Rocket Draft will come in three steps:

Step I:  What was the process of building and creating your launcher?  What materials did you use?  What techniques did you use?  Remember that the criteria here is that anyone should be able to read your paper and recreate a functional launcher.

Step II:  What was the process of building and crating your vessel, and how did you launch the vessel?  What materials did you use?  What modifications did you make and why?  Remember that the criteria here is that anyone should be able to read your paper and recreate a functional vessel similar to yours.

Step III:  What observations did you make during the launching process?  Did this lead you to make any changes in your launcher or vessel?  If so, what changes did you make and why?  What data did you collect and why?  What made your launcher most effective?  What variables did you test and how did you test them?  What did you find out?

At this point you should be able to write most of steps 1 and 2, but not necessarily finish them.  We are just starting step 3, so you should hold off on writing that one.

Let me know if you have any questions.

Mr. H

Discussion

Above is the outline that I put on the board, but one thing that I want to emphasize is that the whole point of this experiment was to figure out something about work and power.  Go back to those definitions and consider what we learned about them with the experiments that we conducted.  Please let me know if you have further questions about this material.

Q1 and Q2

Q3 data

Water Wheel Draft

Below is an example of the quality of draft that we expect from this experiment.  I have not had extensive time to proof it, so please excuse any errors.  Hopefully the gist of what we are looking for comes through.  Use this as a model for your draft.  We will work on the discussion section of the paper tomorrow in class.  I would like to have a draft of this paper due Friday October 28.  My intention will be to read it during the day and get comments back to you before you go home, so you can finish it over the weekend.  Please get started on this tonight!

Let me know if you have any questions.

Mr. H

Introduction

To begin our exploration of the physics and mechanics of water, we decided to build a water wheel.  Water wheels have been in use since well before the present.  Water wheels were used in Rome to grind grain in mills.  Wheels were used in China to grind grain, hull rice and crush ore.  In Medieval Europe water wheels were used also to grind grain.  In the Middle Ages water wheels were used commonly for crushing ore and for processing sugar cane, wheat and rice.  Today water wheels are less commonly used, although they are coming back into fashion as power generators.  (I expect you can add more detail to this history part, I just give a brief overview).  

There are three types of water wheels, an overshot wheel, and undershot wheel and a sideshot wheel.  (Can you think of any advantages of any of the designs that you might put into the paper here).  We are going to build an overshot wheel to test some basic ideas of mechanics.  

The two variables that we are going to investigate are work and power.  We defined work as ______, and power as _______.  To learn more about these concepts we built a water wheel and tested its ability to do work.  Using our water wheels, we set out to answer the following questions:

 What is the maximum weight that our water wheel will raise given a constant flow of water?

Does the rate of the flow of water matter for the maximum weight, or rate of wheel doing work?  If so, what is that relationship?

Is there a relationship between raising small weights long distances and large weights small distances?

I expected that:

1

2  What were your expectations for each of these questions?

3

Materials and Methods

To build the waterwheel we used a 2 (or 1) Liter bottle, a cork and a wire to use as the axle.  To start we divided the bottle into thirds so that we ended up with three cylinders, the top, which included the lid, the middle, which was open on both ends and the bottom.  We used the middle section to create the paddles of the wheel, the bottom as the base for the water wheel, and the top section as a funnel to deliver the water to our wheel.  To build the wheel, we took the middle section and divided it up into 8 equal arcs (each being 1/8 of the circumference of the bottle).  Then we took our cork and also divided the circumference into 8 equal sections.  Using a razor blade we cut a line down the length of the cork to a depth of about 5 mm at each of the 8 sections.  Then we carefully placed the sections of the bottle from the middle into the slices in the cork (see diagram*).  Next we took the wire, sharpened one end and threaded it through the center of the cork.  To finish the water wheel, we took the bottom section of the bottle and cut a V out of the edge to allow water to spill out the side (see diagram*).  Finally we pierced a hole into the sides of the bottle, perpendicular to the V, and hung our wheel in the base (see diagram*).  

After our water wheel was constructed we attached a string to the axle with a dixie cup attached to it so that we could add weight (again, see diagram*).  

*I did not draw diagrams, but we expect that you will.

To answer the above questions, we used the following protocol.

Question 1.  

To answer this question we set the height of our funnel at 10 (or 20) cm.  We also used a rate of ____ mL/sec to test the maximum weight.  We measured the rate of flow by pouring 1 L of water through our funnel and recording the time it took to flow through.  We measured ___ times and took the average flow.  Finally to find the maximum weight we did ___ trials adding weight after each trial until our wheel could no longer raise the amount of weight in the cart.  When we reached this limit we weighed the cart.

Question 2.

To answer this question we set the height of our funnel at 10 (or 20) cm.  We used a constant weight of ____ g in the cart and tested the rate of lifting (in cm/sec) and the total height raised using 1000 mL of water.  We varied the flow of the water ___(3)_ times using flows of ____ mL/sec, _____ mL/sec and ____ mL/sec (repeat for actual number of trials).  We recorded the height that the weight was lifted and the rate at which it was lifted.

Question 3.

To answer this question we used a weight of ____ g in the cart and a flow of ____ mL/sec.  Then, using a constant volume of _______ mL we measured the height (cm) and rate (cm/sec) that a small weight (____g) and a large weight (____g) were raised by the wheel.  

Results.  (notice that there is no interpretation here, just a record of what we found)

Question 1.

We found that at a rate of _____mL/sec that our water wheel was able to raise ____ g.  

Question 2.

We found that with a flow of ____ mL/sec that our wheel raised ___ g an average of _____ cm at an average rate of ____ cm/sec.  We found that with a flow of ____ mL/sec that our wheel raised ___ g an average of _____ cm at an average rate of ____ cm/sec..  Finally, we found that with a flow of _____ mL/sec that our wheel raised ____ g an average of _____ cm at an average rate of ____ cm/sec.

Question 3:

We found that with the same flow of water at a rate of _____ mL/sec that it raised a weight of (small mass) g an average of _____ cm at an average rate of ______ cm/sec.  We also found that with the same rate that it raised a weight of (large mass) g an average of ______ cm at an average rate of ______ cm/sec.

Discussion:

We will work on this together in class tomorrow.

Welcome

Welcome to 10th Grade Physics.  I've created this blog to help keep track of topics covered in class, but also to create a space for you to share, ask, think and brainstorm; with your teachers or with your peers.  If you'd like to be added as an author to the blog, send me an e-mail (address on the paper syllabus you got in class) and I would be happy to add you.  Otherwise, feel free to use the comments section.
Thanks,
Mr. H

Syllabus

Tenth Grade Physics                                                                                       

Mr. Hatfield and Mr. Poleson

Portland Waldorf School                                                                              

Fall 2011                                                                                                              

Blog Address:  pwsphysics.blogspot.com

In this block we will cover the basics of motion and the mechanics of water.  We will also investigate the history of mechanics and how its applications have helped to shape the world that we inhabit.  Students will participate in experiments, thought projects and brainstorming.  Ultimately, through this block, students should gain a greater understanding of many of the objects that they use in their everyday lives. 

Material:

I expect we will cover, at a minimum, the following topics:

·         Acceleration

·         Velocity

·         Flow

·         Gravity

·         Rotation

·         Pressure

·         Stream head

·         Surface Tension

·         Buoyancy

·         Potential and Kinetic Energy

Grading:  I will evaluate grades using the following rubric:

Main Lesson Book:                          30%

Projects:                                          25%

Class Participation:                          15%

Quizzes                                           15%

Homework/Drafts                           15%

Participation:  Students will receive a daily participation grade.  This grade will reflect each student’s attention to the material presented and participation in labs and discussions.  Students that are absent will receive a participation grade of zero for the day, no matter whether the absence was excused or not.  When students return to school, they must come see us to find out what material/assignments were missed.  At that point, for excused absences, we will change the participation grade accordingly. 

Late Assignments:  Will be accepted according to the policy stated in the student handbook.

Quizzes:  You can expect at least 1 quiz and should be ready for more.

Projects:  This block will be project intensive, and the projects will generally be in groups.  We expect that you will remain engaged and ensure that all group members have the ability to participate equally.

Drafts:  We will collect three drafts from you during the block to help you to improve your writing.  These drafts will count towards your HW grade.