<p>Yeah, east. I had no idea; I thought it was negative and that it repelled the leaf.</p>
<p>Shouldn’t the rod be positive because the leaves move closer together after the rod contacts the pole.</p>
<p>I thought the rod was coming close to the leaves, and that repelled them. Did the question say that they made contact?</p>
<p>yeah it showed two pictures, one before the rod contacted the pole and one after the rod contacted the pole. The leaves were closer together in the second picture.</p>
<p>I remember being certain of my answer. I believe I put a positive charge on the rod, since the leaves moved closer together in relation to the first picture.</p>
<p>^^I know there were two pictures, but I remember seeing that the leaf <em>insert fancy device name</em> is shown in figure 1, and when a charged rod is moved near it, the leaves move together as shown in figure 2. I don’t think it mentioned contact; the two figures were to show the leaves moving closer.</p>
<p>Yeah. Therefore, the rod was positive.</p>
<p>Was one of the answers momentum changes while the object is rotated or something?</p>
<p>Undisputed answers so far:</p>
<p>antimatter question: positron
water is boiling: upper most straight part
Index of refraction: sin 60 / 1.5
Given initial velocity, mass, and stopping time: 1, 2, and 3
Force x time = change in momentum
What led to the nuclear model: gold foil experiment
Skydiver jumping off of a plane: potential energy > kinetic energy
Throw ball a up and ball b down at same initial velocity. Whats the velocity of ball a: v (same as ball b)
Half covered lense: full object, but decreased intensity
Index of refraction is 4/3: wavelength is 3/4
Which waves will result in the least disturbance: 6 + (1/2)wavelength
Man is standing underneath water: only choice 1 (the bird and the tree appear to be higher than they actually are)
Particle question where you know the rotational speed of the giant ball with a slit in it: you can only find the speed of the particles
Students climbing stairs - heaviest one
Pv = nrt : t increases as q increases
Heaviest: neutron
Concave mirror: virtual image
Convex lense: real image both small and big
acceleration due to gravity: 1/9
Theta and initial velocity one: Just increase the initial velocity
Worker kicks the bucket: 2 m
Must be electrical field: point charge
Must be magnetic field: bar magnet
Ammeter question (based on drawing from ImageShack® - Online Photo and Video Hosting
Highest: 1 and 2
Lowest: 4 and 5
Vector direction for electric field: West
Vector direction for negative point charge: East
Mass of object in pulley problem: 1.2 Kg
Projectile: net force is constant, direction of net force is constant, angle of net force with path is changing
Object rotating around planet: net force is constant, direction of net force is changing, angle of net force with path is constant (always perpendicular to path)
Speed of light question: 10^-13 J
Traffic light question: All colors except red are absorbed
Piano question: wavelength and period both decrease
emf question with coil and battery: current is induced in all cases except when the coil and magnet have the same velocity
Firetruck question: Velocity of truck + velocity of sound in air
Velocity of puck after collision: 4 m/s
Elevator: 24 N
Graph displaying vertical displacement as a function of time: Vertical spring and rippling tank
Heat transfer question: 4 watts
Difference between sound waves and light waves: polarization
Mass falling through air: 1 and 2 are right, but 3 is wrong (Adding mass doesn’t ■■■■■■ its fall)
Superconductor question: 0
Capacitance question: 2 V
Dark room question: tungsten
Pendulum question: Decrease the length
Electric rod question: It was positive
Box moving with constant velocity on a rough surface: The force of friction is equal to the appied force.</p>
<p>Disputed questions:</p>
<p>None</p>
<p>What was the answer to the question with plank’s constant and a given frequency?</p>
<p>What was the answer to the question with the sound wave passing into a medium?</p>
<p>Only the first choice was correct, right? I think it was 3.3 times 10 to the power of something.</p>
<p>E-14 or the like? And that means the rod is negative then. If the rod repelled the leaves, forcing them together, then it must have had a negative charge.</p>
<p>^^I don’t exactly remember this question.</p>
<p>yeah all you had to do was multiply the frequency by planck’s constant, right?</p>
<p>Do you agree with the sound wave question?</p>
<p>For the electric rod question, the leaves originally had a negative charge and then moved closer together. Thus, the charge on the leaves had to have become less negative. So, the rod must have been positive.</p>
<p>No, I’m pretty sure there wasn’t contact. By moving the negatively charged rod closer, the leaves were forced together.</p>
<p>And I don’t remember the sound wave question.</p>
<p>sound wave:answer was A
plank constant: multiply by frequency, answer was C</p>
<p>for the heat transfer, the thickness was 4, so the answer was 3W</p>
<p>A was just choice 1, right?</p>
<p>The answer to the heat transfer one is already on the list</p>
<p>luceverita, can you verify that all of the answers on the list are correct?</p>
<p>I think these are not correct in the list:
- current was highest in 1 and 4 and smallest in 2 and 5
- Heat transfer was 3W not 4W
I am not sure about the mass-pulley question</p>
<p>and yes, sound wave was choice 1</p>
<p>For the current question, I didn’t know the exact numbers. I based the numbers on a drawing someone had posted earlier. </p>
<p>I’ll change the heat transfer one. I dont even think 4 W was an answer choice. </p>
<p>The mass-pulley one was correct because of the scale reads 10 N then the block has to weigh slightly more than 1 Kg in order to account for the weight of the scale, which is 0.2 kg.</p>