Official SAT Subject Test - Physics - June 2015

@mlgtrickshot I am 100% sure that the increment was by 1cm. There were 24cm and 26cm marks, and there was one tick in between them.
@jamanda i chose the one with one decimal place. II i think

2m

@Coctopus, yes, I think that’s right, because lengths shorten when they approach c, so the asteroid, which isn’t moving, would have the longest length.

Is the Sparknotes curve accurate? About how many can you get wrong to get a 750?

What about the question about how to increase the temperature of the gas? Pushing and pulling the piston? Adding or removing heat?

Push piston, add heat

And for (11) wasn’t there no force (magnetic) because the charge is at rest?

I don’t know how to delete my comment, so I’m leaving this lorem ipsum here.

I think 4 and 5 were questions with point changes and points on x- and y- axes.

But I’m talking about the diagram with the three question that showed a wire and a positive charge at rest on the right hand side.

The first question asked for the force on the charge of the wire is positively charged (something like that).

The second question asked for the force on the charge of there was a current in the wire running upward. (This is the one I am wondering whether there is any force on the charge or not).

The third replaced the charge with a cable.

  1. voltmeter connected in parallel, ammeter connected in series What was the question here? Could we redo it? An answer was 18 photons. The question was how many photons of 5E14 Hz would have the same energy as 6 photons of 1.5E15 Hz = 15E14 Hz so triple 6 = 18.

@Aegon6 To answer both of those questions, I said in the first one that the force is repulsive on the charge because they have the same sign, so it is to the right. The second one I don’t remember exactly, but resolving it given your parameters, we’d have no force since the velocity of the positive charge is 0. However, I do remember that in the second part both of them were wires, and both had current flowing in them. Therefore, there was a force in that case.

@Coctopus wasn’t the question about the photons said: how many 1.5E15 equals 6 5e14?

@Aegon6 OHH SORRY I forgot lol I remember my initial answer was 18 but then I caught myself (sorry for propagandizing) yeah the answer was 2 photons, yes?

Yes, I got two too

2 photons

Is speed at the bottom 10sqrt(3) m/s?

Yes, I got that too

Wasn’t the proton moving to the right though?

That was what I thought during the test. But later I realized that the proton was at rest (it moved to the right in the question before that when the wire is positively charged). Hope I am wrong.

And what about the question with a ray of light traveling from one medium (a) to another (b)? The light refracted to the normal in medium b.

fa = fb and lambda (a) > lambda (b) ?

i believe the light slowed down as it was diffracted to the normal so Va>Vb Na<Nb