OCR Advancing Physics G492 ~5 June 2013~

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We did it, but I don't think it helped much. As long as you make sure you know some potential errors, and you actually know how to calculate gravity from the results, I can't really think of much else to do with that article. It's the speed of light one I'm struggling to prepare for.

How would one calculate gravity from a set of results like that?

Reply 101

liomeeringca

How is everyone feeling for tomorrow? Personally I find some questions really straight forward like ones on waves or quantum, but I get so stuck on mechanics. It doesn't help that I don't take maths either. Hopefully I'm just overthinking things.

What about you?

Reply 102

m00c0w

Can anyone explain Q10b on the May 2012 paper please? Really don't understand it despite looking at the mark scheme.

Reply 103

Matterhorn

What topics do any of you guys find the most difficult when it comes to doing exam questions on them?

Posted from TSR Mobile

Reply 104

liomeeringca

Original post by Matterhorn

What topics do any of you guys find the most difficult when it comes to doing exam questions on them?

Posted from TSR Mobile

Mechanics, mechanics and more mechanics. I never know which suvat equation to do. And questions that say 'prove this formula' or 'show that this formula is correct' when the formula looks like a cat walked across the calculator.

Reply 105

ArchieL

Original post by m00c0w

Can anyone explain Q10b on the May 2012 paper please? Really don't understand it despite looking at the mark scheme.

Sure thing. Imagine x and y as different components first of all.
So therefore for the x direction: u=12m/s. We can say that v therefore is the component of this speed when the direction is changed by 40 degrees. By the cosine rule therefore: v=12cos40. We then take the difference of those speeds and divide it with the time (1.6) to gain the mean acceleration.

Same thing with y, but we use the sine rule (as it is not an enC(os)losed angle) => 12sin40. Take u=0, and v=12sin40, and then take the difference (-12sin40) and divide that with 1.6 to get the mean acceleration.

I hope that helps.

Reply 106

upthegunners

http://www.youtube.com/watch?v=b-B2W1PuuWY

music to get you pumped and in the zone

Reply 107

liomeeringca

Does anyone know if we are able to retake this exam? Presumably in June if we are allowed to since January exams are being scrapped :mad:

Reply 108

ArchieL

Hey guys, I found the digital copy for the prerelease questions at my college, I think they're really helpful! I don't have the mark scheme, but I have most of the answers so feel free to ask :smile:

Prerelease questions, themes, etc:

https://docs.google.com/file/d/0B_oAdOqohPhAbTlObWxkUEJucHM/edit?usp=sharing

(Pretty) Comprehensive revision notes:

https://docs.google.com/file/d/0B_oAdOqohPhARXphYmx6cGZPVDQ/edit?usp=sharing

(edited 10 years ago)

Reply 109

upthegunners

Original post by liomeeringca

Does anyone know if we are able to retake this exam? Presumably in June if we are allowed to since January exams are being scrapped :mad:

we are

Reply 110

Mathletic

Could someone help me?
How do calculate uncertainty?
How do you calculate %uncertainty?
How do you calculate resolution?

Many Thanks and Good luck to everyone tomorow, make sure to READ questions properly.... (otherwise you will have to resit like me :P )

Reply 111

marseille_h

Original post by ArchieL

Hey guys, I found the digital copy for the prerelease questions at my college, I think they're really helpful! I don't have the mark scheme, but I have most of the answers so feel free to ask :smile:

Thanks for sharing :smile:

Reply 112

Mathletic

Original post by Matterhorn

What topics do any of you guys find the most difficult when it comes to doing exam questions on them?

Posted from TSR Mobile

Deffinatley Pre release stuff, but in general the questions are tricky to understand, I think thats the hard part, realising what the question wants etc.

I find some of the graph Qs hard where you have to match the best suitable shape of a graph to different variables, but generally just the manor Qs are presented is tricky!

Reply 113

marseille_h

Does anyone know how to calculate the uncertainty of a gradient? :smile:

Reply 114

ArchieL

Original post by Mathletic

There are some great YT vids on the subject, but..
Uncertainty = http://www.thestudentroom.co.uk/showthread.php?t=227989
% Uncertainty = https://www.youtube.com/watch?v=1dTn2pt5PuA
Resolution = Smallest observable change: In the case of a digital display, the amount of d.p, in a graph it's how many units 1 box represents.

Reply 115

AndItsOllie

Original post by ArchieL

Hey guys, I found the digital copy for the prerelease questions at my college, I think they're really helpful! I don't have the mark scheme, but I have most of the answers so feel free to ask :smile:

HaHa, CSFC I see. Geoff Flloyd, what a legend!

Who did these section C notes, our class never saw them.

Reply 116

ArchieL

Original post by AndItsOllie

HaHa, CSFC I see. Geoff Flloyd, what a legend!

Who did these section C notes, our class never saw them.

Haha, you know it! Geoff's retiring this year

Also the section C notes were Tim's work this year, he rustled them out as soon as the prerelease came out! The physics dept. at csfc are so hyped on caffeine it's unreal.

(edited 10 years ago)

Reply 117

iAkash

Original post by liomeeringca

Does anyone know if we are able to retake this exam? Presumably in June if we are allowed to since January exams are being scrapped :mad:

Its probably a bad idea to even start thinking about resits so close to the actual exam.

Reply 118

marseille_h

This might seem straightforward but I'm a bit confused:

A car has an acceleration of 0.86g. Calculate the time it takes to reach a velocity of 27m.s-1.
g=9.81

v=u+at
so t= (v-u)/a

is g=acceleration in this case and the acceleration of the car they give we take it as u and v=27 ?

Reply 119

liomeeringca

Okay so I'm doing part (b)... and get a funny looking answer, so I check the mark scheme...

Where do you get 169ms-1 and 900ms-1??? I thought it was 13ms-1 and 30ms-1. Could someone please explain?