It’s possible to use tools you learn in one part of the program to explore other parts of the program… here’s an example. In Problem 3.33 of Wolfson you should have generated parametric equations for x(t) and y(t) to describe the motion. After looking up how to build parametric plots in Desmos, I created an interactive graph of the solution, complete with sliders allowing you to adjust values for angles and accelerations (with conversions from degrees to the radians Desmos prefers for calculating sines and cosines built in).

Here you can see the power of doing your work symbolically. Once you enter the formulas, it’s really easy to explore how the results depend on various parameters. A solution obtained by early substitution of values would not be easy to translate into a computer tool like this.

Hi all,

I have now uploaded an example of a problem solved in the format required for Revisions in the (too-?) long post on physics quiz revisions from last week. You should peruse this before you finalize your quiz revisions (which are due 9 AM Wednesday). Remember that the revision should be written on a separate paper (or papers) from any (optional) corrections you make on other parts of the quiz. Both the revision and the original quiz (including any corrections you may choose to make) should be turned in Wednesday. Quiz corrections may be made either on the original quiz or on a separate document, as you choose.

As a reminder, your revision is essentially a solution, formatted along the lines of the IDEA problem solving strategy, to the following problem:

A sprinter runs a 100 meter race. Starting from rest, their acceleration is 4.5 m/s² for the first 2.5 seconds of the race, after which they run at a constant velocity the rest of the race. What will be the sprinter’s total time for the race?

Solutions to the Chapter 3 Physics homework

As it turns out, there are several notebook checks in the works soon… Please be aware of what you need to do for…

• Physics Lab: All Physics Lab Notebooks will be checked this week. Please bring your Physics Lab Notebook in Tuesday October 17 (field trip day). John will come by the chemistry lab to collect them. If you are not in the chemistry part of the program, please try to bring in your notebook before 10 AM (so we don’t need to take them along on the field trip).
• Chemistry Lab: Chemistry Lab Notebooks will be checked in Week 5; stay tuned for details.
• Math Problem Set Notebook check: Math Problem Set Notebooks will be spot checked during the Week 5 Midterm Exam as described in this post.

• Blank copy of Math Quiz #3
• Math Quiz #3 Revisions are due 9am Mon. Oct. 23
  

• Who should submit a Math Quiz Revision? All students are invited to submit a Math Quiz #3 Revision for as many problems as you choose to revise and resubmit.

• Math Quiz Revision Detailed Guidelines
  • You may utilize any resource available to you, but submitted work must reflect your own personal understanding of the material.
  • The care you take in presenting your work will be considered when evaluating it, so pay attention to organization, neatness, etc.
  • Revisions must be neat, complete, and presented in a logical, clear-to-understand fashion, on a new copy of the quiz.
  • Please do not re-submit original quiz – that is for you to keep.
  • Since these are revisions, a higher standard will be used to evaluate your responses. Essentially, your revised solutions should be of the highest quality you can produce.
  • You may revise any problems you choose, and must present a complete solution to any problem you choose to revise (not just a part of a problem).
  • For multiple choice/fill-in-the-blank type questions, your revised solution should completely and clearly explain your reasoning (even though no explanation was required on the original quiz).

From chemistry faculty member Dharshi Bopegedera (bopegedd@evergreen.edu):

“I am looking for a few student volunteers from M&M to do science with kids in the public library to celebrate National Chemistry Week.

• We are going to the Olympia Public Library on October 25^th. We will be there from 2:30-5:30. We can provide transportation to and from the college.
• I will provide simple, hands on, lab activities for our students to conduct with K-12 kids.
• We usually get about 45-60 kids in the library.

The theme this year is “chemistry rocks”. Your students would be just perfect (even if they know very little of chemistry or geology!). From past experiences, this has been a rich experience for our students regardless of their age, class standing, or knowledge of science.

I will appreciate it very much if you would please announce to your class and ask your students to send me an email if they are interested.”

Complete All Problems in your Math Problem Set Notebook. Bold underline problems also due via WebAssign by 6pm on Fri. Oct. 20.

• 2.7: 7, 13, 16, 39, 41, 42, 43, 48(a), 55.
• 2.8: 3, 7, 10, 12, 16, 27, 30, 32.
• 3.1: 15, 29, 31, 43, 44, 45, 46, 47, 49, 54, 58, 63, 65.

Note: Math Problem Set Notebook spot checks will occur week 5 Wed. Oct. 25 in class during the Math Midterm Exam – please bring it with you to class on that day. Feedback will be given on evidence of: engagement, attempts to complete, using solutions to correct.

• Math Problem Set #3 Solutions
  • Compare these solutions to what is in your Math PSN.
  • Make notes, corrections, or complete problems using a different color ink directly in your PSN.
  • This (along with looking over lecture notes) will serve as excellent preparation for the Math Quiz.

• Chemistry: McMurray & Fay 4.1 – 4.8
• Math: Stewart 2.7, 2.8, 3.1
  • Math Reading Response due via WebAssign 6pm Sun. Oct. 15
• Physics: Wolfson 4.3-4.6
  • Physics Reading Response due via MasteringPhysics 8pm Sun. Oct. 15

First, if you have not returned your Quiz 1 revisions, including the original quiz as well as any additional corrections you would like to make, please do so as soon as you can. Some of you did not get Quiz 1 back until Wednesday, so I’m happy to give you a few days extra to complete revisions. But I would like all of them in by Monday, Oct. 16.

Below is a “clean” copy of Quiz 2:

Download (DOCX, 25KB)

You may choose to correct any part of any question on your original quiz (or on a clean copy) and turn that back in with your revision. In addition, you will be expected to turn in a revised solution to what amounts to question 2d from the quiz (whether or not the original answer was correct). The revision is not a correction (though it can also be a correction!) but an opportunity to work on technical communication skills and deepen your understanding of the concepts, as outlined in my post on the revision assignment.

It may be helpful for your revision to approach your work as if 2d were simply the following homework problem:

A sprinter runs a 100 meter race. Starting from rest, their acceleration is 4.5 m/s² for the first 2.5 seconds of the race, after which they run at a constant velocity the rest of the race. What will be the sprinter’s total time for the race?

What you should notice about the quiz is that parts a-c were an effort on my part to guide you to a solution. In part a I invited you to consider what kind of motion this problem represents. It is not constant acceleration throughout (I gave an nonzero acceleration for the first 2.5 seconds; but what is the value of acceleration after 2.5 seconds? Something different!) so you cannot treat the entire sprint using the equations governing constant acceleration. You can, however, break the sprint into two parts, each of which can be analyzed with those equations. Parts b and c asked you to consider just the constant acceleration during the first 2.5 seconds and find the velocity and position at the end of that time period. Beyond offering you extra opportunities to show what you’ve learned and possibly hinting at a method of solution, there was no need for me to ask those sub-parts. Indeed, in MasteringPhysics problem 2.21 about the car approaching the stop sign simply asks for the required value of acceleration, leaving it to us to figure out how to break the motion into segments we know how to model.

Please turn in your revised solution, along with any desired corrections, on Wednesday at 9 AM. Feel free to contact me with any questions about this assignment!