sound suggested answers

[angelboykevin]

Q11 was a question about pressure variation in an open ended tube, where it was vibrating at its fundamental frequency. It asked, at the midpoint P, what the standing wave looked like. It gave two choice of straight lines (for the midpoint P) and two choices of what looked like just normal looking sinusidal waves... I chose the one with a straight line as I thought at the point P there is a flat line, but hey.. who knows

alot students im my school choosed what u choosed, but i didnt,, still not sure who is correct

i dont reckon it was a straight line
im going with option A (fingers crossed)

what was the question again? the pressure  time graph at P or the pressure variation time graph?
if its pressure time graph then i think should b A, but if its pressure variation time graph, since its a antinode, the pressure cariation should always maximum, then a straight line should be correct,
btw, i hope A is correct cos i choose A

[methodsboy]

20phon?
40m?
6dB?
that's all i can recall

[almostatrap]

i don't think a pressure antinode implies constant pressure, but a maximum fluctuation of pressure.

[Spluff]

Yeah, this is what I got.

[methodsboy]

Anti-node  represents pressure changing. i.e not constant. Someone else can re-word it

Just ask Thelma 

[avram_grant]

Anti-node  represents pressure changing. i.e not constant. Someone else can re-word it

Just ask Thelma 

Thelma pwns

[krzysiek]

Q11 was a question about pressure variation in an open ended tube, where it was vibrating at its fundamental frequency. It asked, at the midpoint P, what the standing wave looked like. It gave two choice of straight lines (for the midpoint P) and two choices of what looked like just normal looking sinusidal waves... I chose the one with a straight line as I thought at the point P there is a flat line, but hey.. who knows

alot students im my school choosed what u choosed, but i didnt,, still not sure who is correct

i dont reckon it was a straight line
im going with option A (fingers crossed)

what was the question again? the pressure  time graph at P or the pressure variation time graph?
if its pressure time graph then i think should b A, but if its pressure variation time graph, since its a antinode, the pressure cariation should always maximum, then a straight line should be correct,
btw, i hope A is correct cos i choose A

On the exam is says "pressure variation" I am uploading a copy of the exam now.

[avram_grant]

yeh its A

[TrueTears]

Last 3 was all A. Triple A.

[avram_grant]

Last 3 was all A. Triple A.

yeeeeezzzz

[tommyk221]

What was Q4?

It asked for the curve a quarter of a period later

[Tildy724]

what was question 4, because I got 'C', not 'B'??

also, im so glad im not the only person who got no A's for the first 10 questions, that was really freaking me out!

[TrueTears]

what was question 4, because I got 'C', not 'B'??

also, im so glad im not the only person who got no A's for the first 10 questions, that was really freaking me out!

The quarter period question was B.

[homghomg1]

Q11 was a question about pressure variation in an open ended tube, where it was vibrating at its fundamental frequency. It asked, at the midpoint P, what the standing wave looked like. It gave two choice of straight lines (for the midpoint P) and two choices of what looked like just normal looking sinusidal waves... I chose the one with a straight line as I thought at the point P there is a flat line, but hey.. who knows

crap... yeh P is a node so it wont move, thus i am also wrong (N)
alot students im my school choosed what u choosed, but i didnt,, still not sure who is correct

Q11) - p was an antinode
it was in the middle of an open pipe with fundamental frequency, therefore it is an antinode, so maximum pressure variation (graph is NOT a straight line)
period is 1/385 s, which = 2.6 ms or something, which corresponds to answer A
i am fairly sure all of OP's answers are right, I got exact same and discussed most of them with other kids

[TrueTears]

Yeah at the antinode, the pressure changes from max - min etc etc so it MUST be sin graph.

That eliminates the straight lines.

Then just check the frequency and you get A.