<p>i had 105 J. i did potental energy (mgh), - dissipated from friction</p>
<p>=/ ru sure??
wait what were your calculations??</p>
<p>I got the same thing with diiamondsss
I looked up the physicists one, its the random guy who’s name starts with H… because all the other ones (even copernicus!) did light/sound related. (Now the better question is how is this in anyway useful to be in our knowledge???)
I’m praying for a humongous curve D: Scanned baron’s for a review since I did phys B (and got a 5) last year… aaaand missed A TON of questions</p>
<p>I said newton, but ha, I honestly had no clue. I just figured that newton was the guy who dealt with mechanics, but who knows.
For Kinetic Energy, I got like 105 Joules. I remember getting a=3.5, and then solving for v with vf^2 = 2ax. vf = root 21. I got KE with 1/2mv^2, where m = 10kg.
the graph about energy lost per hour confused me too.
hard test.</p>
<p>do you guys know anything about how the physics one is traditionally scored? what percentage correct fits what range of scores? how many do you think i could miss/omit to stay in 700+?</p>
<p>oh and i got 3/4, copernicus, and unchanged for the diameter one (the equation is Fg=Gm1m2/distance right? i was thinking that the earths width is almost negligible compared to the distance between moon and earth, and certainly wouldn’t be significant enough to double or halve anything)</p>
<p>what about the capacitance question, where it asked for voltage. to help spark some memories, i recall getting getting c=v/d for the question before.
also, for the question about what’s wrong with the picture, i put the ammeter is put in the wrong place, because none of the other choices seemed wrong.
there was a spring question also, where a block was inbetween two springs. was the graph curvy or straight. i know it went above and below the axis, i just couldn’t decide if the acceleration was constant or changing (constant - straight, changing - sinusoidal)</p>
<p>whoops, not c=v/d, but Electric field = v/d</p>
<p>i got 105 J on that last question</p>
<p>i put same for e=v/d. and the spring one was sinusoidal because its being slowly cushioned on both sides to its slow points. its like a smooth motion i dont think it would be straight lines. and i remember questions like that on tests this year.</p>
<p>how am i supposed to know that copernicus did that?? =[[[
yeah the ammeter was in teh wrong place
the voltage in the capacitor is the same as the emf in the battery after a long time
the graph of the spring was sinusoidal.</p>
<p>ahh!! for the last question i used conservation of energy
mgh-F(friction)d=KEfinal <–did anyone else do that??</p>
<p>the voltage is a capacitor is V=Ed
so E=V/d</p>
<p>hey gregb can you explain how you did the last one? i put 45</p>
<p>^ i did! but i got 105J …</p>
<p>^^darn do you remember the numbers in that problem???</p>
<p>yes i used cons of energy too but i just used it to think and not work out the numbers. that frictional force was pretty big compared to the component of gravity thats actually pulling the block down so i figured that it wouldn’t have much kinetic at the bottom because it probably lost a lot to heat b/c of friction</p>
<p>^whoa i don’t remember those numbers lol i thought the block was smaller</p>
<p>I got 105J and 4/3</p>
<p>Fblock = 100 N. F downhill = 50 N. Ff = 15 N. F total = 35N down hill. F=ma. 35N=10kg x a. a=3.5. vf^2 = 2ax. x=3m. vf=root 21. KE =1/2mv^2. KE = (1/2)(10)(21) = 105 J.</p>
<p>does this help?</p>
<p>oh then what about the weird question with the coil and the two bar magnets on the top??
the question asked for what would happen to the current with the magnet on the far left…</p>
<p>and then the question about the impulse, where three equal masses split, and it asked for the velocity and quadrant of the third mass…???</p>
<p>and then the one with the graph asking for the initial room temperature during cooling?? anyone know these??</p>
<p>the answer was that the current was in the same direction. with the north pole headed towards the coil, induced emf is increased, so current acts in the opposite direction. As the south pole is headed away, induced emf is decreasing, and the south pole is the opposite of north pole, so essentially the two negatives cancel out and the current continues in the same direction, its hard to explain if you haven’t learned induced current and motional emf.</p>
<p>its in quadrant 2 at 5 m/s</p>
<p>20 degrees celsius, since the room was at a constant temperature.</p>
<p>haha i somehow remember the mass of that block being 4.5kg</p>
<p>yeah and with the question about the elevator with the scale
what did you guys get??
- what is the force on the scale when the elevator accelerates up??
- " " down
- what is the force on the scale when the cables break?</p>