Re: [Phys-l] [ncnaapt] New Physics CST Questions Released!

["Krishna Chowdary" <professor.head@gmail.com>]

Below is a link (copied from bc's original post) to the test in question.
I've also posted my comments below to the weblog referenced in bc's post.

http://www.cde.ca.gov/ta/tg/sr/documents/rtqphysics.pdf

> > The fifteen new questions are items 1, 2, 10, 12, 16, 23, 27, 32, 34,
> > 40, 41, 46, 54, 58, 60.

I'm uncomfortable with all of the questions on the first page. I'll look at
the other questions when I have time. But here are some comments on the
first 4 questions.

1) The phrase "most easily" bothers me. I typically make plots using a
computer program, and I am very comfortable inputting data into a
spreadsheet or a database.

2) What does "real-time" mean in this context? In fact, I can make graphs of
displacement vs. time and velocity vs. time using all the tools provided.
And further, a typical motion detector directly measures position vs. time
and _calculates_ velocity vs. time. Also, lots of students do video
analysis. What about students who have never used these particular measuring
devices?

3) I'm literally aghast that the answer is "human error". Sorry that I don't
have anything more constructive to add, but I really dislike this answer.

4) Answer choices A and C are _both_ valid. From the image, I conclude that
A accelerates downward while B moves at nearly zero acceleration. If the air
resistance of A is smaller than its weight, it will accelerate downward. If
the mass (and thus weight) of the object is larger than the air resistance
for the period pictured, the overall acceleration of the object would be
also be downward.


--
regards
-Krishna