<p>sorry, wrong thread</p>
<p>I think 5 is way too small, because then the thing you’re measuring it with has gone through 1000 half lives, meaning that it is 1/ 2^1000 the original sample product. That was the same concept for why I didn’t put 5 x 10^6, but I’m not that sure of the latter</p>
<p>ModelCX8, I think the scale measures the the change in length of the spring as a function of the force applied from both sides, not the net force. When one steps on a bathroom scale, it does not read 0, even though the net force on the spring is, in fact, 0 N. (weight - normal force)</p>
<p>I put 5000 also, although I’m not entire sure if a greater half-life would be more or less accurate.</p>
<p>This test was hard comapred to Blue Book and other old tests. Hope to break 750+</p>
<p>Wait wut, there wasn’t a spring on the diagram o.O</p>
<p>It was a scale, no?</p>
<p>For the air resistance thing, wasn’t it decrease in acceleration? Since gravity is constant, and as the velocity increases, air resistance increase and decrease acceleration, isn’t it?</p>
<p>Oh my goodness i am not good at ap physics,dont remember any equations and i am taking it in june. I am done</p>
<p>Wow, I feel like I screwed myself over on this test.</p>
<p>yeah no work on equipotential lines
tension is the correct answer, coz f=n/2l*root( tension/linear mass density)
there was a quiestion on vectors which i think was incorrect-there was nop option wid northwest( the one with the girl cycling 15 km/h north and wind 15 km/h east to west)
what did u write for the question on waves with the path difference of 1m?? i presume it was constructive interference hence max amplitude.</p>
<p>yeah solar cell was the answer( a only)</p>
<p>what was the answer for the loop with a magnetic field and force towards right?</p>
<p>yeha 5000 would be correct, because that way the mass of the sample would be in whole number-exactly half of it, as compared to being in fractions for the other half lives</p>
<p>oh my GOSH
i think…
OH MY GOD
i worked out answers…and forgot to BUBBLE THEM IN.
oh my god.
OH
MY
GOSH</p>
<p>That felt too easy for the first 1/3 or so, then it got pretty difficult/weird. I ommited 2 and know i got about 3 wrong - similar to my Math II experience (got an 800), so im not sure what to think. For the tension one i put 20N (im still not sure about this), and I had no idea with the Bohr model.</p>
<p>and, i put like 5 x 10^6 or whatever was the biggest number was for the half life question. wouldn’t it make sense to want as much substance as possible to minimize error? like imagine measuring out .005g of something as opposed to 5000g. it seems more accurate with the larger the sample. thoughts?</p>
<p>yes you want a half-life as big as possible to be more accurate</p>
<p>however, if the half-life is greater than the time which has passed then you wont be able to tell how long it has been.</p>
<p>lets say you were looking for samples of an isotope of some element which has an half life of 5 x 10^6. when youre looking for it, you dont know how long it has been since that mummy was made or whatever.</p>
<p>if theres 1000 of those particles (lets say a human body usually has around 1200 in their body) ), how will you know it was made 5000 years ago? its going to be less accurate since you only know the half-life of a substance, not their quarter-life or tenth-life or anything. so the answer is 5 x 10^3 because its the greatest number where you also know that theres exactly half the original number of particles in the mummy</p>
<p>I already got 10+ wrongs so far…</p>
<p>@nkhlgeorge:
The one with the vectors would have been southwest because it was asking about a flag on the back of a bicycle. The girl was riding north, so the flag would have blown south, and there was wind from the east, so toward the west. Add them together and you get southwest.</p>
<p>ugh, I think I got that spring scale one wrong, it has to be 20N – and speed of light for the rocket, how could I be so stupid!!! then the waves problems, I’m begining to think that I thought sound waves were transverse again (i’ve done that before) rather than light waves— ahhh!!!</p>
<p>what was the one with the electron microscope ( i omitted that one )?</p>
<p>Oh, and what about the one with the changing the magnetic force on a particle next to a wire?</p>
<p>@nkhlgeorge and shaedow
since the bicycle is moving at a constant velocity, the flag will not blow to either south or north.</p>