<p>Ug of gravity is not that. it is Gm1m2/r. by the way weight has little to do with this cuz u have to solve it the other way, equating mgh = Ug = Gm1m2/r.</p>
<p>oh right, my bad, just woke up a few minutes ago. i definitely shouldn’t do physics while still in bed. hahaha.</p>
<p>is radiation pressure or polarization going to be on the exam?</p>
<p>whoa… what is that… i dont even know haha
i believe its not gonna hurt, as i have never seen those in my practice exams, or the CB exams that i have right now.</p>
<p>how many MCQs and FRQs do you have to get right to get a 5?</p>
<p>There’s a really good calculator that you can play around with here:
[AP</a> Pass - AP Physicsb Calculator](<a href=“http://appass.com/calculators/physicsb]AP”>http://appass.com/calculators/physicsb)</p>
<p>if there aren’t 8 questions…either 7 or 6…what do we do with the calc?..</p>
<p>Hey, can you guys help me out with this? </p>
<p>Pipe X of length 3.0 m is open at both ends. It produces a note of frequency of 28 Hz when the air in the pipe vibrates in its fundamental harmonic mode.
Pipe Y is close at one end and also produces a note of frequency 28 Hz when the air in the pipe vibrates in its fundamental mode. The best estimate for the length of Pipe Y is?</p>
<p>
</p>
<p>e=mc^2</p>
<p>total energy of an object:
e=mc^2/(sqrt[1-v^2/c^2])</p>
<p>Is conduction, convection and radition on the test at all?</p>
<p>@vaeliant</p>
<p>solve for v from pipe x using v=2Lf since it’s open ended.
once you get v for x use it for pipe y, but use v=4Lf since it’s closed at one end</p>
<p>someone back me upon this though! 
haha</p>
<p>Vaeliant, is the answer 1.5 m and yes theblusrstillblu, that is how you do it.</p>
<p>why would you solve for v?
i thought v is always 343 m/s</p>
<p>343 m/s is the speed of sound at room temperature.</p>
<p>Quick question, on the equation sheet the formula for the force of gravity is given as,</p>
<p>F = -(GmM)/r^2 … what’s with the negative?</p>
<p>To signify an attractive force, I’m assuming.</p>
<p>The negative means the force is attractive (i.e. the earth isn’t pushing you away with it’s gravitational force).</p>
<p>Oh, okay, so it’s like with Coulomb’s law…except this can never be positive</p>
<p>just look over convection and memroize formulas for radiation and conduction
i doubt their gna have too much on that</p>
<p>RoyGBiv</p>
<p>In order of increasing frequencies</p>