Unit 5 Physics Edexcel A2 and Edexcel IAL

Does anyone have the jan 2010 unit 5 paper and mark scheme ?

Does anyone know if I can get by with saying 1 light year is 3x10^8 * 60*60*24*365.25 ?

And 1 AU is 3x10^8 * 60 * 8

Or do I have to remember them.
And does anyone know a good way of remember parsec to light year conversion, 3.26 right?

What are the materials that control rods and nuclear reactors are made out of?

Control Rods: Cadmium and Boron.
And about Nuclear Reactors, you are asking about like what components it's made of?

Not sure, I think it was Carbon or something,but you needed to remember Boron control rods and the material of something else in the reactor.

That's the moderator you are talking about. Moderator is used to slow down fast moving neutrons.

That's the one, thanks.

Does anyone know what Edexcel deems the correct penetrative properties for each radiation?

Alpha can't get through paper?
Gamma needs thick lead?

I never know if Beta can or cannot go through a this aluminium sheet.

Some beta may be able to get through a very thin sheet of aluminium.

Your picture says the opposite..?

"Although the beta particles given off by different radioactive materials vary in energy, most beta particles can be stopped by a few millimeters of aluminium."

Source: https://en.wikipedia.org/wiki/Beta_particle

So what would you put in an exam.

Please could you explain how to get to the answer for this question.

Correct Answer:

I think it's A because of this reason that nitrogen is heavier than helium so mass is inversely proportional to speed. So, greater the mass, lower the speed.

Thanks for that. Thats the only explanation I had for their answer too but it still doesn't make sense. Only I thought because it doesn't say there's the same number of molecules in each sample you could increase the number of molecules of helium beyond the number in the nitrogen sample so it has a larger mass than the nitrogen sample. This would then create a circumstance where it had equal or smaller mean square speed as <c^2> = 3kT/m so if T is constant as stated in the question, increasing m will alter the <c^2>.

It's probably just me always reading way to far into a question loosing me easy marks! But can you spot a mistake with my logic?

Thanks for that. Thats the only explanation I had for their answer too but it still doesn't make sense. Only I thought because it doesn't say there's the same number of molecules in each sample you could increase the number of molecules of helium beyond the number in the nitrogen sample so it has a larger mass than the nitrogen sample. This would then create a circumstance where it had equal or smaller mean square speed as <c^2> = 3kT/m so if T is constant as stated in the question, increasing m will alter the <c^2>.

It's probably just me always reading way to far into a question loosing me easy marks! But can you spot a mistake with my logic?

Ok i've worked out where my logic is wrong. It's because m in the equation refers to the mass of an individual molecule, not an entire sample. Hence it's as simple as you say where greater mass causes lower speed. Thanks!