<p>heyy im scared about AP Physics. anybody wanna cram with mee? :p</p>
<p>well, i feel like i don't even wanna care for this test anymore since this is my LAST test!!!!!! yay!</p>
<p>same here, this is my last one.......</p>
<p>wanna tell me how to find escape velocity? or the minimum energy for escaping? ~_~ We never learned this.</p>
<p>escape velocity?? there's a formula for that.
hmm lemme find it.</p>
<p>here you go.</p>
<p>v(esc)=(2GM/R)^(1/2)</p>
<p>G obviously is the universal gravitational constant and M is mass of the earth and R is the radius of the earth. :) -well at least if you're trying to escape from earth.
and i think....the minimum energy thing... you probably get the escape velocity and solve for it. not sure tho.</p>
<p>you can find escape velocity by setting the kinetic energy formula equal to the formula for gravitational potential energy (1/2mv^2=GMm/R) It's the velocity at which there is no mechanical energy in the system.</p>
<p>Let's study!!!!:)</p>
<p>THANK YOU!!!! YAY! I got that question now :).........</p>
<p>Anything else...anyone has questions about, let's talk about it :)</p>
<p>for escaping v
set E = K + U = 0
U = -GMm/r
K = 1/2 * mv^2</p>
<p>so K = -U
1/2 * mv^2 = -(-GMm/r)</p>
<p>V = (2GM/r)^(1/2)</p>
<p>On circuits, say theres a resistor that is after the battery, and then a resistor and either an inductor or capacitor in parallel (these are after the initial resistor). Does anyone want to go over like what happens when switch is first closed, after a long time, and then once its open for each of the 2 cases. THese always mess me up, and they are about 3+ questions on the MC and are always appearing on the FR.</p>
<p>Just remember: after a long time, the current through a capacitor is zero, and the emf of an inductor is zero.</p>
<p>And for a charged particle to move and feel a force in an electric field, it has to move perp to the field? or parallel</p>
<p>parallel</p>
<p>magnetic field, then perpendicular</p>
<ol>
<li> The equation of motion of a simple harmonic oscil¬lator is d2x/dt2 = 9x, where x is displacement and
t is time. The period of oscillation is
(A) 6 (B) 9/2 (C) 3/2 (D) 2/3 (E) 2/9</li>
</ol>
<p>nvm I get it now. K=9 m=1</p>