Is anyone doing ocr physics P7 tomorrow?

Showing 1 to 9 of 9


Posted: 29-05-12 14:44 by rhona

no sorry, I am doing AQA physics unit 2 tomorrow though :D

Good luck ^_^

Posted: 29-05-12 15:26 by Nuha

yep I am, why do you need help with something?

Posted: 29-05-12 18:57 by Bruno Russell

Yeah I am as well, good luck with it!

Posted: 29-05-12 19:58 by Sohail

I was wondering if any of you could help be my teacher said you could work out the proberbitily of an asteriod hitting earth by using the graph at the bottom of the prerelease her caculations were

1/ 0.6 = 1.67 then divide by a million she got the 0.6 by reading up from 2500m asteroid diameter why did she read up from there are why is it divided by 1 really sorry i dont understand! please help me

Posted: 29-05-12 20:32 by Sophie

You will not get asked that in the exam, because there are too many variables on the graph that could give different results - for the moment I would focus on key things that are likely to come up, such as cepheid variables, mirrors and lenses, the death of a star, protostars, emmiting light spectrums, planet and star movements across the night sky, eclipses, nucleur fussion and Curtis/Shapley/Hubble.

As for the pre-release material they will may ask you if a meteriod had not hit for a long time how much is the increased risk of one hitting, or about cause and effect. They could ask you to explain the weaknesses and strengths in an article, bias in an article, peer review and its advantages in the scientific community and general questions on the extinction of dinasours.

Posted: 29-05-12 20:38 by Bruno Russell

I'm doing this exam aswell, and can i just say that the pre-release is HORRID. On the 7th paragraph, it says:

"Iridium is very rare in the Earth's crust and very common in asteroids. Immediately after the iridium layer, there is a dramatic decline in fossil abundance and species..."

When i read this, i think it means that after when you did down into the ground, and get to the iridium layer, there will be no fossils above the iridium layer. But what happened to the dinosaurs???? The conclusion that my teacher came to was that they were vapourised in the asteroid impact.


Modified once, last modified by RFC1871 (Eden32) on Wed 30th May, 2012 @ 09:00

Posted: 30-05-12 08:59 by RFC1871 (Eden32)

No its means, after the iridium layer there are fossils straight away (from the extinction) however folloqing that there are hardly any - suggesting that there was a drastic decline in species and fossils, because of the meteroid hitting (which is proven by the fact that there are increases iridium levels and lots of iridum is found in meteroites.

Posted: 30-05-12 09:06 by Bruno Russell

So immediately after the iridium layer, there are fossils, then after that, there aren't?

Posted: 30-05-12 10:56 by RFC1871 (Eden32)