The Official AP Physics B Thread

<p>I second that. For me, the magnetic field and the double-slit are the difficult ones because my teacher really didn’t cover them thoroughly.</p>

<p>obviously everybody has different strengths/weaknesses.
I myself found #1 easy, along with induction/thermo/fluid questions.</p>

<p>optics/atomic were iffy.</p>

<h1>1 was easy, i messed up in #3 ( i think i got… 10/15?)</h1>

<p>the rest were easy >.></p>

<p>my teacher covered optics and quantum stuff last so those were the easiest for me. I had just taken the quantum test like a week before the test.</p>

<p>all our tests were cumulative, so my teacher tested me on everything we had learned on every test.</p>

<p>that way we’d never forget it :P</p>

<p>Wouldn’t 2d be incorrect because theta isn’t actually what you’re measuring from? 90-theta should be correct. (What you measure from should appear on the force diagram and theta doesn’t - 90 minus theta does.)
Does this make sense? It’s difficult to put into words, haha.</p>

<p>Hi,
I was wondering if there was anyone here with access to all the actual AP tests dating back to the 1980s. I don’t need an answer key, but if you could provide one that would be awesome. Either email or PM me. Thanks!</p>

<p>Why is it C?</p>

<ol>
<li>An empty sled of mass M moves without friction across a frozen pond at speed vo. Two objects are
dropped vertically into the sled one at a time: first an object of mass m and then an object of mass 2m.
Afterward the sled moves with speed vf . What would be the final speed of the sled if the objects were
dropped into it in reverse order?
a. vf /3 b. vf /2 c. vf d. 2vf e. 3vf</li>
</ol>

<p>isnt physics B suppose to be easier than physics C? how does it compare to environmental? lol</p>

<p>it’s alot harder than enviornmental^</p>

<p>@Mordred Since there is no friction force, dropping objects onto the sled has no impact on its velocity.</p>

<p>^ Thank you</p>

<p>freaked out for physics. How to study?</p>

<p>Yanks, that solution is not entirely correct for solving this problem. </p>

<p>This is a conservation of momentum problem. Thus, for the case of dropping objects onto the sled, the only thing that matters is the final mass of the sled. In case 1, the mf will be (M+2m+m)= M+3m. In case 2, it will me M+m+2m=M+3m. The two final masses are the same so the final speed for each case will be the same or vf.</p>

<p>^Yes but because the pond is frictionless the mass does not matter.</p>

<p>I haven’t really seen many released exams… can anyone tell me if there are any concepts that the free response questions asks about every year in some way? Or are they totally random? Some say it is totally unpredictable but I don’t know…</p>

<p>Same here… but if I get a 3 or below my life will be over…</p>

<p>I have some of the study guides (PDF)-will trade for some of the actual old AP exams-PM me please for more info…</p>

<p>Number 10 on 2009 MC. Why is it C? : What is the change in internal energy of the gass for the process bc? (answer is 0J)</p>

<p>Can someone explain numbers 3, 8, 16, and 17? </p>

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