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AQA Physics A Unit 2 5th June 2009 [New Spec]

The angles were like 63.9 and 67.8

Tension was 22000 x 9.81 and then divided by 4 and the second part was 22000 x 9.81 x 32

Not a bad paper overall... :smile:

Reply 61

El Guerrouj

***Hannah***

That was easy... :smile:

What was the how do you know it's not more than second order or what ever... :confused:

Put sin90 into the diffraction grating equation and put the rest of the numbers in and rearrange it to find n, n came out as 2.83 so it was impossible to reach order 3

Reply 62

MarcusTheEskimo

What was the plastic elastic one? I put because the decreasing force was less than the increasing force for the same extension, so it didn't break or something.

And for the same question, the area under the graph was the energy stored?

Reply 63

Susant

1

***Hannah***

That was easy... :smile:

The first question was just 1/2mv^2 and mgh, don't know what people are on about when they are randomly minus'ing stuff?

:

Same here, I'm not sure what othes are going on about.

Reply 64

MarcusTheEskimo

El Guerrouj

Put sin90 into the diffraction grating equation and put the rest of the numbers in and rearrange it to find n, n came out as 2.83 so it was impossible to reach order 3

Or just use n=3 and you get a sinx value greater than 1, which never happens.

Reply 65

Izzwizz0

what was the answer to the question about the displacement on point Y in half a period?

Reply 66

kayn

El Guerrouj

Put sin90 into the diffraction grating equation and put the rest of the numbers in and rearrange it to find n, n came out as 2.83 so it was impossible to reach order 3

i did it by using the order n=3 you then get like sin1.3 or something bigger then one , which the inverse off to get the angle is impossible , thats how i shew it , anyone else do it this way? its right 100%

Reply 67

***Hannah***

calvinuk

lambada/D

Rounded DOWN to the nearest whole number, 2.80 -> 2

Yup that's the one!

Couldn't think of it in the exam... :frown:

I wrote something stupid like substitute n= 3 to make the equation d sin theta = 3 lambada and some explanation about that... :shy2:

Lol a few stupid mistakes here and there, hoping for an A overall... :yep:

Reply 68

furry747

10

calvinuk

lambada/D

Rounded DOWN to the nearest whole number, 2.80 -> 2

Same.

For maximum orders, you insert sin90 into the dsintheta=nlambda equation

Which then leaves you d/lambda. This gives an answer of 2.8.......

Which you round down because you cannot have point something of a nth order. Therefore, only 2nd order is present.

Reply 69

MarcusTheEskimo

Susant

Same here, I'm not sure what othes are going on about.

The part after wanted you to account for the difference in KE and GPE.

GPE was 8000J
KE was 8700J
His pedalling provided 2400J

I put the extra 700 was gained from the pedalling, but energy is lost as friction/sound/thermal.

Reply 70

kayn

MarcusTheEskimo

What was the plastic elastic one? I put because the decreasing force was less than the increasing force for the same extension, so it didn't break or something.

And for the same question, the area under the graph was the energy stored?

i put that because it returned to its original length

Reply 71

Susant

1

By the looks of it, the grade boundries will be high. Hopefully a lot of (ermm...) less intelligent chavs (pardon me!) took the test and will bump it down a bit :smile:

Reply 72

kayn

MarcusTheEskimo

The part after wanted you to account for the difference in KE and GPE.

GPE was 8000J
KE was 8700J
His pedalling provided 2400J

I put the extra 700 was gained from the pedalling, but energy is lost as friction/sound/thermal.

i wrote about the energy is lost as friction sound and heat aswell but no one else seems to have done

Reply 73

MarcusTheEskimo

Izzwizz0

what was the answer to the question about the displacement on point Y in half a period?

I put things like it will move to the greatest negative displacement, which is the amplitude, then move back to where it was before when the half period is up where it is on the point of moving in the positive-displacement direction.

Reply 74

***Hannah***

El Guerrouj

Put sin90 into the diffraction grating equation and put the rest of the numbers in and rearrange it to find n, n came out as 2.83 so it was impossible to reach order 3

I did write when you substitute n = 3, d sin theta =/= 3 lambda

1 mark more... :eek:

Reply 75

MarcusTheEskimo

kayn

i wrote about the energy is lost as friction sound and heat aswell but no one else seems to have done

Really? I don't see any other way to do it.

Reply 76

***Hannah***

MarcusTheEskimo

The part after wanted you to account for the difference in KE and GPE.

GPE was 8000J
KE was 8700J
His pedalling provided 2400J

I put the extra 700 was gained from the pedalling, but energy is lost as friction/sound/thermal.

Which question is this?

It is the one where I wrote GPE depends on mgh, as he pedals downads, h decreases therefore mgh decreases and is converted into KE?

Reply 77

Izzwizz0

what was the time till the bike comes to rest?? i got 10 seconds??

Reply 78

furry747

10

Izzwizz0

what was the time till the bike comes to rest?? i got 10 seconds??

I have a feeling it was 20.

Reply 79

El Guerrouj

MarcusTheEskimo

Really? I don't see any other way to do it.

I added something about how when he moves off the hill onto the flat bit he loses gpe because he loses the horizontal component of the weight force he had on the hill.

AQA Physics A Unit 2 5th June 2009 [New Spec]

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