<p>and for the questions that had to do with the rod and the particle, and then the particle changes into the other rod with current going up, did you get 1. away from wire 2. parallel 3. toward the wire?</p>
<p>Yeah for the snail question I got 2.0 m/s, which is total distance/total time. For the momentum question I got the graph with the straight line; the area underneath was simply length (x-axis) x width (y-axis), like a rectangle.</p>
<p>Can anyone else verify the following?</p>
<p>Magnitude of electric field for parallel plate capacitors: V/d
Slope of graph with V and I (I believe I was on the x-axis, and V was on the y-axis); slope was 0.33 ohms</p>
<p>First few matching questions:
- Longest wavelength: the first one: <a href=“http://physics.info/waves-standing/[/url]”>http://physics.info/waves-standing/</a>
- Highest amplitude: this one was self-explanatory, the one with greatest displacement to y-axis
- Fundamental: also the first one from the above link</p>
<p>woudn’t the longest wavelength be the one that didnt cross the x axis at all?</p>
<p>edit: jk, i agree; I thought you meant the first graph on the test, but yes i picked the first one thats on that website as well
and i also agree with the rest of the answers</p>
<p>yes, i got V/d. kind of weird since they mentioned C in some of the answer choices
and yes 0.33 ohms
and the longest wavelength and fundamental, that was E on the test wasnt it? if it was, that is what i got.
what about for the accuracy questions? for 1.7358 or somehting. I, II, or III?</p>
<p>Yeah that was what I put: the one that didn’t cross the x-axis at all, since for that one the length was lambda/2.</p>
<p>In the link:</p>
<p>[Standing</a> Waves - The Physics Hypertextbook](<a href=“http://physics.info/waves-standing/]Standing”>Standing Waves – The Physics Hypertextbook)</p>
<p>Go to “One dimension: two fixed ends” and the first wave there (the one that did not cross the x-axis) was the one I put for #1 and #3.</p>
<p>what did the third one ask again? (for the wave questions)
also, did you say that temperature affects resistance of a wire?</p>
<p>what represented the fundamental frequency</p>
<p>and i said no it didnt, but i think it does…since temperature affects the length, which does affect resistance…</p>
<p>Wait did the charge around the wore move perpendicular or parallel? I thought it was for sure perpendicular but I went over it really quickly.</p>
<p>hmm i think i said perpendicular as well…the last one in that set said if the charge is replaced by another wire with a current directed up, was the force towards the wire?</p>
<p>Yup!! Didn’t put it though… Oh well!</p>
<p>it was definitely parallel…try the right hand rule again. F = qvB</p>
<p>Yeah I put parallel too; using the right hand rule, the force should be directed upwards, along the plane of the page.</p>
<p>The force was toward the wire, since for two current-carrying wires parallel to each other:
- The wires attract each other if they have the same direction of current
- The wires repel each other if they have different direction of current</p>
<p>And temperature does in fact affect resistance. Refer to page 195 of Barron’s SAT Subject Test for Physics.</p>
<p>Hold up!! How does temp affect resistance, there is no temp in R=pL/A</p>
<p>True temperature is not in the equation: R = Constant x L/A, but I’ve found some sources that support a relationship between temperature and resistance.</p>
<p>As always, I may be wrong, but here are two links I found:</p>
<ol>
<li>[Temperature</a> Coefficient of Resistance](<a href=“http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html]Temperature”>Temperature Coefficient of Resistance)</li>
<li>[url=<a href=“http://en.wikipedia.org/wiki/Electrical_resistance_and_conductance]Electrical”>Electrical resistance and conductance - Wikipedia]Electrical</a> resistance and conductance - Wikipedia, the free encyclopedia<a href=“Go%20under%20the%20%22Temperature%20Dependence%22%20section”>/url</a></li>
</ol>
<p>Ya its that temperature just isnt proportional to resistance but it still affects it.</p>
<p>For the last question with the sound waves, was the answer, changing intensity as she walks away? Because of interference right?</p>
<p>Also for the atom that emits a photon, the internal energy decreases or something right?</p>
<p>To confirm, the factors that affect nuclear decay rate one is none of the above?</p>
<p>Were the answers to the thermal questions, water higher specific heat than ice, 33 J?</p>
<p>for the last question, it would be alternating LOUD soft LOUD soft. cause of diffraction.
and yah, the internal energy decreases.</p>
<p>i dont remember the thermal question. what did it state?</p>
<p>alternating loud and soft loud and soft would correlate to the answer of changing intensity of the sound, because loudness of a wave is determined by the amplitude which in turn is the intensity of the sound wave.</p>
<p>Also, diffraction when you have only 1 source, bending through a aperture. This scenario is different, because there are two sources. It even stated in the problem that at a certain point, the two sources were in phase with .70 m, which would suggest that at that point, there is constructive interference</p>
<p>Here’s a compiled list. Add/critique/debate where necessary.</p>
<ol>
<li>A (acceleration and net force - both negative)</li>
<li>A (acceleration and net force - both negative)</li>
<li>A (acceleration and net force - both negative)</li>
<li>Two stationary net charges - no points had 0 force</li>
<li>Two stationary net charges - outside points on x-axis deflected to the right</li>
<li>Standing waves - highest amplitude (obvious)</li>
<li>Standing waves - lowest frequency (top one of this picture <a href=“http://img.ultimate-guitar.com/_img/columns/zeg/3-4-1.jpg[/url]”>http://img.ultimate-guitar.com/_img/columns/zeg/3-4-1.jpg</a>)</li>
<li>Standing waves - largest wavelength (top one of this picture <a href=“http://img.ultimate-guitar.com/_img/columns/zeg/3-4-1.jpg[/url]”>http://img.ultimate-guitar.com/_img/columns/zeg/3-4-1.jpg</a>)</li>
<li>Charged particle repelled from wire (3 question set)</li>
<li>Two wires with current in same direction attract (3 question set)</li>
<li>Charge deflected parallel (3 question set)</li>
<li>Largest change in momentum = straight line graph with largest area under curve</li>
<li>asteroid would appear to have the greatest length to 0.1c</li>
<li>Galileo didnt discover expanding universe </li>
<li>Superconductivity = low temperature electronic devices</li>
<li>Light bulb only gave off radiation</li>
<li>Convex mirror produced the virtual image (image was behind mirror and smaller)</li>
<li>Image formed at 15 cm on other side of convex lens.</li>
<li>Image of child was 10.5m from adult (real adult not image)</li>
<li>If the switch were closed the bulb NOT in the parallel would have the greatest current</li>
<li>The consensus is that all 3 brightness would change if the switch would close –> however i disagree and only the ones in the parallel would change (see my post #67)</li>
<li>Curved acceleration-time graph - increasing speed until constant speed </li>
<li>Resistors are affected by length, area, and temperature</li>
<li>Change in internal energy = -12J</li>
<li>Total kinetic energy of ball being dropped = 120J</li>
<li>question 74: direction cannot be found because magnetic field direction is not known</li>
<li>last question: alternating loud, soft (changing intensity)</li>
<li>average speed of the snail 2m/hr</li>
<li>magnitude of electric field = V/d</li>
<li>slope of graph = .33ohms</li>
<li>16 decays per second
32 None of the above affected radioactivity of an element</li>
<li>Atom loses energy when emitting photon</li>
<li>amount of time doesnt affect the heat i think Q=mc(delta)T</li>
<li>smaller hole and larger wavelength would make single slit diffraction larger</li>
<li>time objects were in contact 0.1s</li>
<li>the force on object makes it go in a circle</li>
<li>linear expansion? 10.006</li>
<li>photon has no mass</li>
<li>i remember getting 36 photons as an answer somewhere</li>
<li>doppler effect = two objects moving relative to each other
42 inducing electric field moving the coil and wire</li>
<li>increasing speed equals increased kinetic energy (pendulum)</li>
<li>force acting against pendulum = decreased kinetic energy, increased potential energy?</li>
<li>voltmeter connected in parallel, ammeter connected in series</li>
</ol>
![http://img.ultimate-guitar.com/_img/columns/zeg/3-4-1.jpg[/url]](http://img.ultimate-guitar.com/_img/columns/zeg/3-4-1.jpg%5B/url%5D){kind=link}
<p>I’m pretty sure one of the answers was 2 photons.</p>
<p>Also the longest length would be from the asteroid itself, because the equation is</p>
<p>L = L0 x rt(1 - (v/c)^2) If you are traveling slower than the speed of light, which is the only thing that can happen, then rt(1 - (v/c)^2) is smaller than 1 so the length of the measured asteroid is smaller.</p>
<p>Also, for the 3 light bulbs question, the reason that all three brightness change is because:</p>
<p>1 of the turns dark completely, circuit is broken for that light bulb. The other one in the parallel now experiences a different voltage because the resistance of the “parallel” is changed. The voltage of the source is always constant. Now, instead of having a parallel that has R/2 resistance and a R resistor, assuming the resistance of 1 light bulb is R, there is only 2 resistors each with R. That means that each one would receive a different proportion of the voltage by ohm’s law, which then correlates to a different current. By P=IV or any similar formula, a different brightness is seen.</p>