Exam Discussion!

[FSH7]

Do you mean on the sound detailed study? It was something like: Joe plays a standing wave of 80Hz into a tube, he attaches a meter which measures pressure variation from the normal air pressure. It asks you which of the choices are correct. I believe 'C' was the meter needle will swing from negative to positive 80 times a second. Another choice was the needle swings from negative to zero 80 times a second.

[isuru.e]

I'm not quite sure about question 8 or 11 either to be honest. I thought that the person would hear the low frequency instruments for longer because of greater diffraction.

Ye i thought i circled that? I'm worried now

[jumcakes]

Do you mean on the sound detailed study? It was something like: Joe plays a standing wave of 80Hz into a tube, he attaches a meter which measures pressure variation from the normal air pressure. It asks you which of the choices are correct. I believe 'C' was the meter needle will swing from negative to positive 80 times a second. Another choice was the needle swings from negative to zero 80 times a second.

I think I wrote D, as it was a pressure node, and the pressure would be the same as that at the open end of the tube, where the pressure is equal to atmospheric pressure. I'm not 100% though.

[Brunette15]

haha maybe she meant higher?

Yeah I meant higher haha 

[KayKay]

I think I wrote D, as it was a pressure node, and the pressure would be the same as that at the open end of the tube, where the pressure is equal to atmospheric pressure. I'm not 100% though.

It's definitely D

[isuru.e]

I think I wrote D, as it was a pressure node, and the pressure would be the same as that at the open end of the tube, where the pressure is equal to atmospheric pressure. I'm not 100% though.

Yee I got D too

[Stew_822]

Although I don't think it will be too much of a hassle, I believe if you used exact/non truncated values the projectile question turned out to be 3.74 metres (3.744something).

Which question was Question 8, if you can remember?

Yeah thinking about it I think I got 3.74 as well.

I got D for that question to, it asked for a pressure node and a node is where the pressure remains constant, so D. An antinode is where the pressure varies, so since they used the word "node" I hoped they just didn't mean an antinode

[wanigara]

Can some upload the paper pls. 

[xdtash]

Yeah thinking about it I think I got 3.74 as well.

Thank god someone else got that, I thought I rounded the wrong way

[Targor]

I think the cut off for A+ might be 125/150, definitely less than last year though. Exam wasn't THAT hard, just covered all the topics well.

[rhys.oo]

in question 1b in motion where the truck had 40 tonne and there were 2 trailers of 10 tonne each. calculate the tension in the rope between the truck and the trailer.
was there friction
and for P=mv what was the mass before and after the collision

[theshunpo]

in question 1b in motion where the truck had 40 tonne and there were 2 trailers of 10 tonne each. calculate the tension in the rope between the truck and the trailer.
was there friction

I don't think there was any friction.

[xdtash]

was there friction
and for P=mv what was the mass before and after the collision

I didn't think about friction because we knew their acceleration. We didn't have to subtract forces to sub into F=ma to get 'a'. So T=mass*acceleration=0.2*20000?
For the momentum question, the locomotive was 40000kg, and each carriage was 10000kg, so after the collision, total mass was 80000kg. I got a speed of 2m/s

[FSH7]

Does no one have a copy of the physics exam? Strange because after the methods one, the solutions were put up almost straight away. How do people get their hands on the exams afterwards anyway?

[xdtash]

how did u get 80000kg

Well the locomotive was 40000kg, and four carriages of 10000kg each. 40000+4(10000)=80000
I really hope I didn't misread the question haha