<p>Anyone up to discussing AP Physics C free-response at 4:00??? (48 Hours Later)</p>
<p>We can make up an AIM chatroom or just do it here on CC....</p>
<p>yea why not, the questions are on cb now</p>
<p>Anyone want to discuss their answers?</p>
<p>for the third problem when it asked you to write a conservation of energy equations, was it for the first one just 1/2kx^2 = 1/2mv^2 and for the second one 1/2kx^2 + mgh = 1/2mv^2 ??</p>
<p>I wasn't sure </p>
<p>=(</p>
<p>yuppp....exactly like that I believe!...did you say that it would or wouldnt be linear??? I put non-linear cuz mgh can be expressed in terms of theta and x..therefore adding a term that is NOT of power x^2. so its nonlinear</p>
<p>thats what i wrote</p>
<p>yay! that's what i put! I said because of the addition of gravitational potential energy, the relationship is no longer linear between the speed and the displacement. hope we're right!</p>
<p>what about the first one??? was there anything special about the graphs??? I just drew a straight line for velocity and curve for x lol i seriously had no idea</p>
<p>wouldnt the mgh term have a trigonometric term since it was inclined at a certain theta</p>
<p>me too ... </p>
<p>oh and for the first one max a ... did you just set the upward forces equal to gravity and that was max a, since if upward forces > gravity it would lift off the air?</p>
<p>There were four forces on the box right??? Normal force upwards, gravity down, F1 to the right and up (theta) ...and frictional force to the left opposing motion?</p>
<p>What about the planet-orbit one??? I know the last part was a Conservation of Angular Momentum problem and I effed that up cuz i overthrought it!!! But did you say that the period would be "less than" cuz period squared is proportional to radius cubed..therefore as one decreases, the other does too...</p>
<p>yeah see they didnt indicate the height though, so you couldnt put like Lsintheta or anything ... (the height wasnt labeled) ... thus i just put h and left the formula in general terms</p>
<p>yeah exi91...I believe I had either cot(theta) or tan(theta) in my problem</p>
<p>period squared is only proportional to radius cubed when its a non-circular orbit (keplers laws) ... that problem still asked about the circular orbit, but i said it decreased since the velocity increased and T = 2<em>pi</em>r / v</p>
<p>yea, the period would be less for the planet one.</p>
<p>how about the last part of the first one (acceleration), did you only have to look at the vertical forces, or did you have to take into account the horizontal force also?</p>
<p>i couldnt remember the value for G, so in part b) my answer is in terms of the constant (G). Is that a problem ... am i not going to get the point if the work is right?</p>
<p>bts, this is what i was asking, too:</p>
<p>oh and for the first one max a ... did you just set the upward forces equal to gravity and that was max a, since if upward forces > gravity it would lift off the air?</p>
<p>i think we're right tho</p>
<p>i hope so. i almost changed it becuase i thought it was too simple and couldn't figure out how that first question could add up to 15 points.</p>
<p>anyone take Electricity/Magnetism?</p>