<p>The magnitude of the frictional force, that had to do with the 100N force applied, was 40N.</p>
<p>Wow we’ve really done amazing this month guys. This List is pretty awesome. </p>
<p>Scores come in such a long time though. June 25th. Good Luck. </p>
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<h2>Consolidated List 70/75 Questions </h2>
<p>v/2L is fundamental frequency for string fastened at two ends
For the graph given about a wave:
–period = 0.01s
–amplitude = 4
–wavelength = 6
For the graph given about potential energy versus distance:
–potential energy at x1 = a
–kinetic energy at x1 = b
the merry go-around is spinning at the speed of 1/2 pi
75) B0 isnt necessary for emf (Confirmed)
the centripetal force decreased by a factor of 4 (F/4)
acceleration (mass?) of the pushed object is 5x 10^6
beta particle emission question: nuclear mass stays the same
the constant force applied on the 5 kg object was 30 N
radioactive decay with half lives after 90 days = 8
Telephone messages —> visual images on screen = fiber optic cables (Confirmed)
students record distance travelled: 10.77 is average velocity (Confirmed)
two magnets are next to eachother:
–1st question: either one or both are permanent.
–2nd question: both are permanent (<strong>split)
Q = cv = 20x10^6
change in kinetic energy of the object is F * d = 60 J
for 73) current is same (E) I1 = I2 = I3 (current stays same in series circuit)
for 74) use resistance eqn. R = PL/A answer was r3(thinnest)>r1(medium)>r2(fattest)
for the beginning like numbers 6-8 given graphs:
–relationship between mass and energy = E = mc^2 = straight line (B)
–relationship between freq. and energy = E=hf = straight line (B)
–intensity of monochromatic blue light (Straight horizontal line) (Confirmed)
optics question with converging lens: same size upside down
for 72) f/cos thetha
71) F = 40 N
First few questions:
–1) momentum of II is greater
–2) momentum is same
–3) momentum is same
optics question with plane mirror at an angle: image is virtual and not inverted (twist page and deal with it as a normal mirror question)
The resulting force of attraction between the two moved is 1 x 10^4 (originally 4e4)
Least affects static shock when getting out of car: whether the engine is on (Confirmed)
Pulley with 2 masses of 50 N each and in equilibrium: Force on the rope is 50 N
The efficiency one being 40% (500K and 300K)
B for the field line diagrams w/ two opposite charges
80m for dropping something off a cliff
“II only” for the one with large and small boxes with temperature transfer (Confirmed)
For the 5 diagrams as choices with a satellite orbitting a planet. Mass and Radius varied.
–First problem, asked which had greates grav. force = answer E (m=2M r=R)
–Second problem = E (m=2M r=R)
Linear Expansion problem:Temp raised from 20 to 22 over to 20 to 30. deltaT raised 5x, so L raised 5x, and the answer = 0.015 cm
Rutherford Experiment problem: The size of nucleus was significantly smaller than that of the atom
Waves interfere with each other and get diffracted at the two slits.
Switched I and III add up to the least resistance, thus the greatest current
Elevator problem: I only
Which of these could make the net force 0: I and II only (I got “vector sum=0, and that some could be in the same direction”, but not that they could be the same magnitude)
Work is the only nonvector quantity
Wave generator (deep –> shallow): The eqn that relates it is s1/lam1 = s2/lam2 because freq doesnt change : Answer = velocity of the waves changes (can’t remember values but used that equation to get ans = 3.2)
Which waves can interfere(sound somethign somthing) Answer: I, II, and III
Negatively charged rod and X and Y are ends of a piece of metal: Answer: voltage / net force = 0 (</strong>split)
Area under F vs t curve = impulse
Two different frequencies: beats (Confirmed)
Question underneath that: resonance (Confirmed)
Question underneath that: quality (Confirmed)
Center of mass of the frame: point D
F/4 for electrostatic force or something like that
pi/2 for person on merrygoround with radius 3 moving 5 rev /s
Center of mass of the frame: point D
Graph of ax + b is linear with a positive slope and y-intercept
The range of the perimeter of the rectangle where the sides were known to a ±.1 value was a range 13.6 to 14.4
A person throws an objects in the air, which graphs represents velocity v.s. time
–answ: the graph with the positive y-intercept that slopes down
Which of the following stays constant for (object)?
–answ: acceleration
What is not true regarding the beta particle?
–answ: Minimum potential energy
A ruler attached to table undergoes simple harmonic motion
An atom emits a beta particle –> another particle must also be emitted
range of the perimeter of rectangle (answer A) from 13.6 to 14.4
Greatest current was least resistance which is I and III
KE of 5kg object = 60 J
Acceleration of ball released from rest is same</p>
<p>Nice job hotinpursuit, the list has doubled since I’ve last looked here.</p>
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<p>I remember this one being 30J though… I believe that was answer choice D and the next highest was answer choice E at 150J.</p>
<p>I’ve added NYEM’s requests after he posted them, so there are some redundancies.</p>
<p>Also I think I thought of another not on the list… I omitted it so I don’t know the answer, but it was asking the max power of a resistor with 20 ohms. Anyone remember this?</p>
<p>Really? I think the question was asking the maximum current you could get from something with a power output of 10 watts and a resistance of 20 ohms. The answer was 1/(sqrt2).</p>
<p>
</p>
<p>Yea that sounds right, it was max current. GJ getting that one.</p>
<p>@ evillion, I also got 30 J for the KE of the 5 kg object, but I’m not sure if that’s right…</p>
<p>Anyone remember the actual question for the 30/60 J one? I remember them giving you information for the potential energy, or maybe that was a different question…</p>
<p>for the the question with the PV graph, where there are two paths X and Y, and it asked which one had the greatest change in U, isn’t the answer E, it cannot be determined since we do not know the heat input for each…, cause the equation is U = Q -W after, all, and we do not know Q</p>
<p>PV = nRT, and U is proportional to temperature. Since the paths both start and end at the same points on the PV graph, the change in temperature (and thus the change in U) is the same for both.</p>
<p>isn’t the equation, U = 3/2 NKT ??, for this case we do not even know which type of gas is used, and how many molecules or moles of each gas is used</p>
<p>Well, it’s probably reasonable to assume that the number of moles is constant during the process…</p>
<p>The change in kinetic energy question was 30 J. Change in KE is just a fancy way of asking for the work done when F=10 and a=3.</p>
<p>yeah i remember thats how i did it and it was quick and easy, but forget #s</p>
<p>Yeah I remember using W = delta KE somewhere… And when you say a = 3, don’t you mean d = 3 where d is distance traveled?</p>
<p>@energize, i didn’t mean that the number of moles did not stay constant, i meant that we did not know the number of moles for any process, X or Y, how can we be sure that the change in internal energy is the same even when we dont know the heat input? thats like saying the accelerations of a 5 kg mass is 3, without even knowing the force applied…</p>
<p>looking back :
the sound one people are looking at i think PI has it right -beats - resonance (DEFINATELY) - and quality
I TOO AM A MUSICIAN hahah
we def did that in physics B</p>
<p>and for the nuclear one with the momentum, the only one that has mass change ( too account for momentum or energy or whatever inconsistancy) was the one that had a change in MASS NUMBER, which is NOT changed by beta decay</p>
<p>Oh sorry! Yes, I mean that d=3, not a=3.</p>
<p>@Tribalz1: We don’t need to know the number of moles or the heat added:</p>
<p>T = PV/nR -> delta T = (P1V1 - P2V2)/nR</p>
<p>We then use the definition for internal energy:</p>
<p>U = 3/2 nRT -> delta U = 3/2 nR (delta T) = 3/2 nR ((P1V1 - P2V2)/nR)) = 3/2 (P1V1 - P2V2)</p>
<p>P1, V1, P2, and V2 are the same for both paths, so delta U is also the same for both paths.</p>
<p>(You can use Nk for nR in these equations; it doesn’t matter, since it cancels out anyway.)</p>