HSC Physics Question Thread

[Kle123]

The answer is A. Could someone please explain?

[jakesilove]

The answer is A. Could someone please explain?

Hey! We want to force the path of the particle DOWN. Remember that electric fields point in the direction that a positive charge will move. So, by adding an electric field denoted in A, we push the positive particle back towards the target. Does that make sense?

[katnisschung]

bonjour!
revising the michelson morely experiment and i was wanting to confirm their result was considered a "null result for two reasons"
1. there were no discernible changes to the interference pattern when the interferometer was rotated

2. the interference pattern would result in two waves in phase (considering the two beams of light are split and travel equidistantly, if the aether existed they probably presumed this..becos one would be travelling with the aether...thus reach the detector faster and result in an interference pattern where the waves were out of phase )
but would result in two waves in phase with the same reasoning--> travelling equidistantly.

idk nothing really said the second reason explicitly..maybe i'm overthinking it. thoughts?

[jamonwindeyer]

bonjour!
revising the michelson morely experiment and i was wanting to confirm their result was considered a "null result for two reasons"
1. there were no discernible changes to the interference pattern when the interferometer was rotated

2. the interference pattern would result in two waves in phase (considering the two beams of light are split and travel equidistantly, if the aether existed they probably presumed this..becos one would be travelling with the aether...thus reach the detector faster and result in an interference pattern where the waves were out of phase )
but would result in two waves in phase with the same reasoning--> travelling equidistantly.

idk nothing really said the second reason explicitly..maybe i'm overthinking it. thoughts?

Hey Katniss! The first reason is the reason, your second one isn't necessarily right, though it is correct in principle. It would be next to impossible to make two separate beams of light travel perfectly equidistantly,  like, a speck of dust would kill that! So there will almost definitely be an interference pattern - It's only if it changes in the experiment that we could have had evidence to support the Aether model

[Kle123]

Hey! We want to force the path of the particle DOWN. Remember that electric fields point in the direction that a positive charge will move. So, by adding an electric field denoted in A, we push the positive particle back towards the target. Does that make sense?

yes thankyou jake

[Bubbly_bluey]

hey guys!
In MnG,there a graph on the relationship between the magnetic flux vs time as the ammature turns.
Assuming that the initial postion is parallel to the field, the graph shows one 360 revolution of the ammature. So my question is: why is this relationship a sin curve? like 3/4 of the revolution the ammature is experiencing maximum flux (b/c lots of field lines are going through it) but the graph shows a minimum. basically imasking why isn't it shape like camel bumps.
Thanks

[jamonwindeyer]

hey guys!
In MnG,there a graph on the relationship between the magnetic flux vs time as the ammature turns.
Assuming that the initial postion is parallel to the field, the graph shows one 360 revolution of the ammature. So my question is: why is this relationship a sin curve? like 3/4 of the revolution the ammature is experiencing maximum flux (b/c lots of field lines are going through it) but the graph shows a minimum. basically imasking why isn't it shape like camel bumps.
Thanks

Hey Bubbly! I'm having a little trouble picturing your scenario, but I think I'm with you. The reason it doesn't look like camel bumps, for starters, comes from the fact that magnetic flux is a vector - It has a direction. So, the magnetic flux through the coil has to be negative just as much as positive because the armature is rotating through a full 360 degrees. The reason why it is sinusoidal is, pretty much, the same reason that the formula for torque has a cosine term, \(\tau=BAIn\cos{\theta}\) - It is just a consequence of the math and the interactions involved, you don't need to explain it in depth!

I can try and explain it a little better if I could see the diagrams specifically, if it helps

[Zainbow]

Hey!
Just a small question: If the question gives us data in, say, MJ, do we answer in joules or MJ as well? (SI or whatever they give us?)

[jamonwindeyer]

Hey!
Just a small question: If the question gives us data in, say, MJ, do we answer in joules or MJ as well? (SI or whatever they give us?)

Hey Zainbow! My policy has always been that using just joules with scientific notation is always acceptable provided they don't specify, but you can definitely use MJ or GJ or whatever they use if that is your preference - You'd get paid for the answer regardless

[Zainbow]

Hey Zainbow! My policy has always been that using just joules with scientific notation is always acceptable provided they don't specify, but you can definitely use MJ or GJ or whatever they use if that is your preference - You'd get paid for the answer regardless

Thanks Jamon 

[Aaron12038488]

I have my practical tomoz, which is the World Communicates Topic. Has anyone  done a prac on this topic and if so any advice will be very appreciative.

[pikachu975]

I have my practical tomoz, which is the World Communicates Topic. Has anyone  done a prac on this topic and if so any advice will be very appreciative.

I can't remember since it was last year but I think we did one with light boxes and refraction of light waves through glass. Should be easy enough I can't remember though if that's even the right topic it's under...

- I do the prac in the second half so I can see how others do it and make sure I do it right.

[jamonwindeyer]

I can't remember since it was last year but I think we did one with light boxes and refraction of light waves through glass. Should be easy enough I can't remember though if that's even the right topic it's under...

- I do the prac in the second half so I can see how others do it and make sure I do it right.

That's the one I did it too, I had to determine the refractive index of glass, some variation on the light box setup is the most common experiment that students get given in this topic!

Similar to pikachu, I remember I did a little trial run of the experiment with quick calculation to check that I get the expected answer, before you get stuck into doing it properly it is nice to know you are on the right track

[winstondarmawan]

How would you do the question in the attachment below?
Thanks in advance.

[Aaron12038488]

Thanks, also is this prac done individually or in groups. I'm so nervous as it is worth 20%.