VCE Physics Question Thread!

[Bri MT]

When you are required to make a cheat sheet anyway for the exam, is it still worthwhile making a separate summary sheet?

I'm not saying to make a separate one, I'm suggesting you improve your already existing one and make it better; and to then use that better version in your exam

[peanut]

Just to confirm, the cheat can be either:
2 A4 double-sided pages OR
1 A3 double-sided page

Is this correct?

[sweetiepi]

Just to confirm, the cheat can be either:
2 A4 double-sided pages OR
1 A3 double-sided page

Is this correct?

Yup!
If you use the two A4 pages, they must be bound by tape

[KiNSKi01]

Don't know how to calculate answer for this question:

A 10m shelf with as mass of 50kg has supports positioned at each end. A mass of 100kg on the shelf is 3 metres from the left-end, a mass of 150kg is 3 metres from the right-end and an additional 200kg mass is 1.5 metres from the right-end.

How do I calcualte the forces on the shelf due to the left and right supports?

[Baylsskool]

So normally a moving conductor inside or being affected by a magnetic field,(key word moving), has induced current into it(not perfect), however in this case, a superconductor apparently only needs to be affected by a magnetic field to have a perfect induced current, am I reading it wrong, or is it that the superconductor doesn't need to move? And if so my question is why wouldn't it need to move to do this, as this contradicts Lenz law??
Use this link for the photo of why I'm asking https://m.imgur.com/a/QL5F2

[TooLazy]

Don't know how to calculate answer for this question:

A 10m shelf with as mass of 50kg has supports positioned at each end. A mass of 100kg on the shelf is 3 metres from the left-end, a mass of 150kg is 3 metres from the right-end and an additional 200kg mass is 1.5 metres from the right-end.

How do I calcualte the forces on the shelf due to the left and right supports?

I used g as 10m/s^2 to make things easier
Also not sure if its correct, haven't done these questions in ages

[BlinkieBill]

Hey,
need help with answering this question.
Why is AC is preferred over DC for electricity transmission?
Thanks

[Bri MT]

Hey,
need help with answering this question.
Why is AC is preferred over DC for electricity transmission?
Thanks

Think about everything you've learnt about power loss in transmission.
Transformers can be used to dramatically reduce this loss (explain how), and transformation only works for varied input  (explain why and how this is relevant to AC/DC considerations)

[Sigma]

Because in AC, distribution losses are less compared to DC distribution losses.
AC Circuit breakers are cheaper than DC Circuit breakers.
The repairing and maintenance of AC sub station is easy and inexpensive than DC Substation.
The Level of AC voltage may be increased or decreased(step up and Step down) transformers.

[-273.15]

Hi guys
do you think its likely that they will ask us a question on inclined planes???

[Bri MT]

Hi guys
do you think its likely that they will ask us a question on inclined planes???

Probably. This might be in the form of banked tracks, connected bodies, etc.

[TooLazy]

Hey,
need help with answering this question.
Why is AC is preferred over DC for electricity transmission?
Thanks

3 main points:

-AC is preferred over DC because it can be transformed. Transformers work on the principle of electromagnetic induction.
More detail: Alternating current (AC) is constantly producing a changing magnetic flux, which induces a current in the secondary coil of the transormer
-The voltage can then be stepped up (using a transformer).
-This leads to lesser power loss in the transmission lines as, there is less current running through them.
  (According to the equation Ploss=I^2 R)

[KiNSKi01]

How do I do this question. I can't get the answer so I'm guessing I'm looking at the question the wrong way  . Im assuming you find 35% of 200 MW and then equate that to the work done over time taken. However when I get to this stage the only equation I know to calculate work done is Force x distance which doesn't make sense in this context. Help!!

[Bri MT]

How do I do this question. I can't get the answer so I'm guessing I'm looking at the question the wrong way  . Im assuming you find 35% of 200 MW and then equate that to the work done over time taken. However when I get to this stage the only equation I know to calculate work done is Force x distance which doesn't make sense in this context. Help!!

If the power station has an efficiency of 35% then   35% input energy = 200MW
Use that to find how much energy is input, and therefore how much fuel must be burnt

[Cassidyhogi]

Can someone please answer this question.
Describe how matter is converted to energy by nuclear fusion in the Sun.
thank you