***June 2014: Physics (US)***

<p>Yeah I agree with PlayerZero, I got the direction of the current-- it was asking for the magnitude of the force, which doesn’t depend on direction.</p>

<p>All of those things affected it I thought :/</p>

<p>I put the magnitude of the wire’s current because I didn’t know what else</p>

<p>yeah, I agree with PlayerZero and infintehamlet</p>

<p>Schoolboy Q aka my profile picture agrees about direction, as direction and magnitude don’t have anything to do with each other</p>

<p>What was the question? I remember putting velocity but I think i’m wrong</p>

<p>Edit:
My thoughts that it was way easier than PR practice test 2. Around same difficulty as PR practice test 1. </p>

<p>as someone previously stated, the answer is Direction of the current. It affects the magnetic force but only the sign, and the question was asking about magnitude. For the speed of the wave i got 40 m/s. The velocity will affect the magnitude since Fb = qvB sin theta, and B = I/r * mu/2pi</p>

<p>What about the one in the beginning that asked for a emf diagram between two opposite charges? Weren’t there two answers?</p>

<p>Do you mean the electric field lines?
I believe one of the two showed 2 charges of equal sign but differing magnitude, and the other showed 2 charges of different sign. The trick was that one of them had the field lines going from charge 1 to charge 2, but the electric field lines around charge 2 were coming radially outward</p>

<p>what you guys get for the waves meeting at a point p and what happens on either side of p- I said decreasing, decreasing relative to the wavelength at p, what you guys put?</p>

<p>I think the answer was decreasing at both sides of P. the difference in distances was 2 wavelengths, meaning there was constructive interference. At P there is a maximum and around it, to both sides, it decreases.</p>

<p>No, I checked and double checked in both diagrams there were feild lines moving from one charge to another. They were both charges of opposite signs.</p>

<p>The magnitude may have been different but it didn’t ask about the magnitude it just asked about the sign.</p>

<p>Yes, the field lines went from one charge to another. But the charge where the field lines ended at had field lines coming out of it. </p>

<p>what about the comet rotating around the sun, was force towards the sun or center of the circle? Also for the force and velocity question, was the answer 2 m/s?</p>

<p>acceleration is always in the direction of the force. Meaning the acceleration was in the direction of the sun (gravitational force). Velocity should be tangent to the path. </p>

<p>for the voltmeter thing, was it just connect the voltmeter in parallel w/ the bulb? And was ‘curie’ the answer to the newton question</p>

<p>For the voltmeter question I got Parallel with the bulb as well. For the “newton” question I got galileo</p>

<p>didn’t newton build on galileo’s ideas? It said all of the following were ‘something to do with newton physics’ EXCEPT? I didn’t think curie had any relation</p>

<p>Curie came after Galileo. I agree with in parallel to the bulb. As for the which bulbs light up, was it 4 of them (I don’t remember which) and when one goes off, the brightness increases because resistance goes down right? Anybody get 2 m/s for the force to velocity graph? What was the answer to the ball in the elevator question; I put straight line up -not sure though</p>

<p>No it just said which one influenced newtons work</p>