OCR Physics G484 - June 2013 Unit 4 (OFFICIAL RETAKE THREAD)

Dont worry guys you did not have to cosnider the number of wheels at all in the question. I specificaly though of this in the exam and reread the question all it asked for was the area in contact with the floor. No consideration of the number of wheels was necessary at all.

1200g=pressure1 x area1

1200g=pressure2 x area2

change area1-area2

Even if there were thousands of wheels, the total increase of area of contact would still be the same proportion, I think. As long as all the wheels are identical with same specific heat capacities, etc. Thinking back about the question, the amount of wheels shouldn't be an issue.

Although, I can't be sure. I can't remember what the whole question referred to! I remember it asking about one particular wheel, whether there were any more to be considered... We'll need the paper again, I guess.

I thought it went pretty well. The only question I'm sure I dropped marks in was the last one. For the change in area question did you guys get something like 5*10-3. And for the for change in velocity question did you guys get 3.2, with the area under the graph being 8 so 8 divided by the mass. And for the example of resonance in everyday life I said tuning a radio, not sure if that is every day though.

What if the car had three wheels?

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http://www.thestudentroom.co.uk/showthread.php?t=2386506&p=43252049#post43252049

Unofficial mark scheme

The grade boundaries are going to be skyhigh. Everyone I spoke to (including those in my class who struggle with physics) said they found it very straightforward, even the "stretch and challenge" questions like the last one calculating the increase in pressure.

Easiest G484 paper to date in my opinion.

I reckon 50 for an A, and then down in increments of about 3 (so B=47, C=44 etc).

And bare in mind that G484 is always marked very tightly to the mark scheme, so people may lose marks on the few written questions.

44 :O :'( ah give up with physics


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Bare in mind that's just my estimation :P

It could well be a lot lower, I was just basing it on my/my classes experience!

If the boundaries go down in 4's then you'll be better placed anyway.