sat II physics question......

Test Preparation
1

<li>A heat engine’s high-temperature source has a mass, m, and a specific heat, c. In a cycle of the engine, as it extracts energy from its high-temperature source, the temperature of that source drops by temperature dT (assume 100% efficiency for this heat extraction). The engine then does some work and then exhausts an amount of energy, Q, into a cold reservoir. What is the efficiency of the heat engine?</li>
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<p>my answer to this question was </p>

<p>1-(Q/mc(dT)) since efficiency is given by 1 - (Q1/Q2) and not (1-Q1)/Q2</p>

<p>but the correct answer is given as (1-q)/mc(dt)</p>

<p>am i right or not???</p>

2

<p>c'mon...........ppl at CC get 800 all da time at physics.........so plz do this question!!</p>

3

<p>bump........... sorry i have really forgotten all my physics in 6 mnths...... :eek:<br>
and i did get 800 and still cant help... :o</p>

4

<p>am i rite or not?????// sum1 help</p>

5

<p>That's wrong, the correct answer was something like.. Qh = Qc + Lost
... or something like that. I took the Physics SAT2 in May, and got a 710, but i'm pretty sure I got that one wrong. During discussion after the test on these forums that was discussed. Try doing a search on it, the post was some time a while ago (the day of the SAT2.)</p>

6

<p>Here's the forum, read through that - it has a couple of the questions/discussed answers on the May Physics SAT2.</p>

<p><a href="http://talk.collegeconfidential.com/showthread.php?t=61044&highlight=Physics+SAT2%5B/url%5D"&gt;http://talk.collegeconfidential.com/showthread.php?t=61044&highlight=Physics+SAT2&lt;/a&gt;&lt;/p>

7

<p>no........this is ques 64 on the sparknotes diagnostic test!!</p>

8

<p>That question is a bit defective (I remember it). The units don't work out correctly. There is no correct answer given in the choices. Don't stress about it.</p>

9

<p>
[quote]
no........this is ques 64 on the sparknotes diagnostic test!!

[/quote]
</p>

<p>opps, sorry!</p>

10

<p>sparknotes is ridiculously hard.. SAT II is easy as hell</p>