<p>okay what should be the raw score for 750+ on physics?</p>
<p>charge on the capacitor as a function of time:
- - - -
-<br>
-
-
-
-</p>
<p>current is just that graph but inverted</p>
<p>(darn didn’t format right =[) but for charge, it should be a parabola approaching a number on the positive y axis</p>
<p>pigs at sea, for the first question, there was a picture that showed perendicular forces. It was the one with the circle. There is centripetal force and tangent force, 90 degrees to each other.</p>
<p>^Ok for both of them I just put E, which was an exponentiall decreasing graph…is this correct?</p>
<p>and yea I got perpendicular for the circle too. </p>
<p>gahhh think I’m gonna miss like -15 now…</p>
<p>hopefully -15 is still an 800…: /</p>
<p>no, the acceleration and velocity are not perpendicular to each other because it was not uniform circular motion
the centreipetal force was at a weird angle, and the horizontal component of the frictional force made the horizontal component of the centripetal force shoorter, so it’s not perpendicular</p>
<p>Really?</p>
<p>It looked like a circle to me.</p>
<p>for the relativistic question, the spaceship’s relative time is 1/sqrt[1-(.7c)^2/c^2], or approximately 1.4 x stationary observer. so if the spaceship sees the probe supposedly moving at 1.3c, it’s moving at c(1.3/1.4) for the stationary observer. so the answer must be .7c<v<c.</p>
<p>it’s not uniform circular motion because its tangential velocity will change (speed of the ball)</p>
<p>^same here…when I added the two vectors the sum seemed to point to the center.</p>
<p>Oh, I think centripetal force may have looked crooked b/c of the point where the force vectors were drawn. </p>
<p>I didn’t think the frictional force mattered</p>
<p>nvm, i get it.</p>
<p>For the spaceship problem, it said that that RELATIVE to the ship, the satellite was moving at 0.6c. Meaning, from an observer on the ship, the ship is stationary, because it’s the reference point. So, this means that 0.7c<v<c, because the satellite is obviously moving faster.</p>
<p>And I forget the actual graph question, but I remember being pretty sure that one involving speed or kinetic energy was a parabola, because it’s 1/2mv^2, so the square means it has to vary exponentially.</p>
<p>^ yeah, that was how I interpreted it, and I put 0.7c<v<c, but I still have my doubts. Speed and KE are different, KE would be a parabola, speed would be a line. The question with a graph i’m thinking of had speed…</p>
<p>the one where the radius increases by 4</p>
<p>the electric force is changed by a factor of 1/16</p>
<p>does anyone remember the girl throwing ball question?</p>
<p>It was 3 m right?</p>
<p>^ yeah, 3m</p>
<p>I thought this was easier than the practice ones I took. Still, there were a few I was fuzzy on, but hopefully the curve will make up for it.</p>
<p>So on the elastic collision, the ball ends up moving negative in the Y direction and positive in the X?</p>
<p>What was the one with the graph of current vs time? After the charge in the capacitor one? I think I put the horizontal line, or something…</p>
<p>And the first law of thermodynamics? I put II and III, because II was obvious and I’m pretty sure the first law is equated with delta U = Q - W.</p>
<p>EDIT: Just wikipedia’d. The first law of thermo question was almost definitely II and III, I think.</p>
<p>for the two balls, i put the big one went negative x and zero y.</p>
<p>dont know if this is right but just assumed since the small ball went straight down the x axis that so did the big one</p>