Vcaa exams....

[Bestie]

For the vcaa 2013 exam question 1a) the assessors report claims I could use x=ut+1/2at^2 and they got 1.74? I got 1.75 using that method and the report says 1.75 is the wrong ans?

And also...
Q6c) shouldn't there be kinetic energy at points q and p? If not why?

Q15b)was I supposed to give it to two sig fig cause I used 18v which is two sig fig? The assessors gave it to 3 sig fig?

Q15c) how do I know whether to use the RMS voltage or the voltage peak?

[RKTR]

For the vcaa 2013 exam question 1a) the assessors report claims I could use x=ut+1/2at^2 and they got 1.74? I got 1.75 using that method and the report says 1.75 is the wrong ans?

it doesn't say 1.75 is wrong. however it says some students use the wrong formula to get 1.75

[speedy]

For the vcaa 2013 exam question 1a) the assessors report claims I could use x=ut+1/2at^2 and they got 1.74? I got 1.75 using that method and the report says 1.75 is the wrong ans?

And also...
Q6c) shouldn't there be kinetic energy at points q and p? If not why?

Q15b)was I supposed to give it to two sig fig cause I used 18v which is two sig fig? The assessors gave it to 3 sig fig?

Q15c) how do I know whether to use the RMS voltage or the voltage peak?

1a) That's pretty weird, but maybe they only marked it incorrect if average speed was used. Not sure though.
Edit: That's talking about velocity, not acceleration.

6c) Basically, at these points the velocity is momentarily 0 - as it is changing direction. Think of projectile motion, vertical velocity is instantaneously 0 at the top-most point of the arc.

15b) Physics doesn't give a shit about sig figs as long as you're not being stupid - ie. 10 decimal places

15c) Power always uses RMS.

[Bestie]

thank you so much speedy!

[Bestie]

whats the difference between magnetic field and magnetic flux? cause on the VCAA 2013 the assessors said: It was important to refer to a change in flux rather than a change in magnetic field.

[PB]

Magnetic field is just the region where magnetic field lines can be found. Magnetic flux is referring to the AMOUNT of magnetic field lines passing through a set 2dimensional area ( like, a loop for example). FYI, this is fairly fundamental knowledge of magnetism, so I urge you to perhaps go back to the textbook/youtube to ensure that you have no gaps in your conceptual knowledge of the topic.

[speedy]

i have another question:
part c?

What's the answer for this one?

[Bestie]

these question please

they are both from vcaa 2009 detailed study