Official Thread For OCR Physics A G484 Jan 2011

the question were u had to describe differences between displacement and amplitude and frequency and angular frequency was stupid and hard :/

wot do u guys think full UMS is likely too be? 53,54,55?

The amplitude was indeed 2.5, and I put the displacement being x=2.5cos(2pif)t + 13 (I think f was 1.22x10^-5) and wrote a note to the examiner saying it must be from the maximum or minimum.

Well, for starters while kWh is not on the syllabus, it does STATE that all previous knowledge is assumed (Gave me a nice easy few marks!)

The amplitude was indeed 2.5, and I put the displacement being x=2.5cos(2pif)t + 13 (I think f was 1.22x10^-5) and wrote a note to the examiner saying it must be from the maximum or minimum.

And the tide does illustrate simple harmonic motion! Not only springs do (I mean a woodwind instrument is a prime example). As long as acceleration is directly proportional to displacement, and is always directed towards the mean it shows simple harmonic motion. Not just springs.

And the satelite one was easy, just equate gravitational force to centripetal force and rearrange having cancelled the small 'm's and the radius.

Bit of a weird paper but none of it hard... or is it just me that thought that? Plus we'd done both Jan and June '10 past papers and specimen and it wasn't really any harder and all on syllabus?

I gave M2 definitions rofl.

Frequency, Oscillations per unit time.

Angular Frequency = Omega = Rads-1 so therefore it's the change in radians per second.

Same! Except I think it's +15.5 rather than +13 since that's the equilibrium position.

Also, according to my spellchecker when I wrote equilibrium above, i can't spell it, so there goes my QWC mark.

Same! Except I think it's +15.5 rather than +13 since that's the equilibrium position.

Also, according to my spellchecker when I wrote equilibrium above, i can't spell it, so there goes my QWC mark.

I thought I'd put 13, as using cos I did it from what is the maximum displacement from the mean, thus any distance will be measured from that point. If you use sin it is from 15.5

the question were u had to describe differences between displacement and amplitude and frequency and angular frequency was stupid and hard :/

wot do u guys think full UMS is likely too be? 53,54,55?

I gave M2 definitions rofl.

Frequency, Oscillations per unit time.

Angular Frequency = Omega = Rads-1 so therefore it's the change in radians per second.

Ahh! I think I just figured out the milk cooling graph!! It should have been a straight line negative gradient, then a flat line because it changes state, then another straight line with a steeper negative gradient!! Lost marks
Did anyone actually do that or am I crazy?

OCR know how to **** things up. I mean, first chemistry, and now this. It wasn't that bad of a paper, but what the **** is kilowatt hours doing in here? What is the definition for it? I just said it was 3.6x10^ something Joules. That SHM question with the tides was **** as well, read minutes instead of hours, so my calculations were all wrong. Realised my mistake at the very end and fixed it, but got the amplitude wrong etc etc.

I got the milk gradient thing fine, took a while to think of which one had the steeper gradient. How did people to the boyle's law graphs? I had like a y=1/x graph for the one on the left, then a y = x one for the one on the right?

How did you work out the mass of the helicopter oO?

You're probably correct, I don't think he is.

If he used 2.5 instead of 5 for A, there's no way +13 would be correct.

As +13 is correct for A = 5. Not 2.5

I bet he didn't even stick it back into the equation to check.