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



Another set of 2cents on a recent post concerning the first 4 questions


|
| 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?

I'm quite uncomfortable by the first two questions as well, they seem to
have nothing to do with standards in physics, but rather with knowledge
of certain set of jargon and/or devices, which aren't really asking
something about physics or core experimental technique.

|
| 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.
|

Normally I'd be aghast as well, and would have preferred something like
"measurement blunder" rather than the often mis-used term "human error".
However, given the other choices, it is rather clear and I'm surpisingly
willing to give them the benefit of the doubt on this one.

| 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.

I suppose the author of this question never passed a standards test; or
maybe perhaps they did . . .

Cheers,

Joel