OCR Physics A G485 - Frontiers of Physics - 18th June 2015

I thought this paper was alright. Good mix of standard format questions and some nice maths ones.
I think I've still done badly because I'm an idiot and messed up basic things.
So definitely can say goodbye to my A* now.
Hope you all did good :-)

Don't know why. But I hate when people 'cry' about not getting an A* lol
An A is amazing :s there is probably 40% that will get a C or a B :>

Reply 1681

chukster97

17

someone go over the horizontal disp question for me?

Reply 1682

Hummi_C

14

Original post by chukster97

i got 1340bq, how many marks would i lose?

maybe a couple, did you not think that was an unusually radioactive banana?

Reply 1683

Lousamnap

3

Original post by G481 Ostrich

You see I would say I got 100/100 but I think that would be a bit of "ostrich" of the imagination

What don't you get!!! ostri and physics DONT MIX!!!!

Reply 1684

chem@uni

9

Original post by actanide

Question 11? was that the Hubbles law thing? I swear that was question 10

There were 11 with one on back

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Reply 1685

Hummi_C

14

Original post by chukster97

someone go over the horizontal disp question for me?

It gave you the distance, 1.8 m and the terminal velocity (call it v, I can't remember its value) therefore time = d/s = 1.8/v.

You calculated the force in the previous question, and since a = F/m and you're given the mass you can calculate the acceleration.

Then use SUVAT from AS to find s (horizontal displacement):

s=ut+1/2at^2

(I think)

Reply 1686

pje1000

1

Original post by matthew6665

Don't know why. But I hate when people 'cry' about not getting an A* lol
An A is amazing :s there is probably 40% that will get a C or a B :>

This is totally subjective. If somebody thinks they have underperformed by getting an A rather than an A* whats the problem?

Reply 1687

Lousamnap

3

Original post by Hummi_C

maybe a couple, did you not think that was an unusually radioactive banana?

Hahahaha!

Reply 1688

L'Evil Fish

OP

18

Original post by matthew6665

Don't know why. But I hate when people 'cry' about not getting an A* lol
An A is amazing :s there is probably 40% that will get a C or a B :>

Because they need them for their offers...

Reply 1689

leroythelost

10

Damn it, I felt good just after the exam then I come here to find out I lost a lot of stupid marks...I need a high A in this for an A in physics but i doubt ill even get an A in this paper

What do people reckon about 135-140ums is in marks for this paper.

(edited 8 years ago)

Reply 1690

Elcor

14

What did people say for advantages of beta over gamma? I said beta is more short-ranged so it's more damaging to the patient, and a smaller proportion of the radiation leaves the body and is detected.

Reply 1691

Hummi_C

14

Original post by Elcor

What did people say for advantages of beta over gamma? I said beta is more short-ranged so it's more damaging to the patient, and a smaller proportion of the radiation leaves the body and is detected.

That's what I got, think (hope) it's right :smile:

Reply 1692

leroythelost

10

Original post by Elcor

What did people say for advantages of beta over gamma? I said beta is more short-ranged so it's more damaging to the patient, and a smaller proportion of the radiation leaves the body and is detected.

I said gamma doesnt cause as much ionisation as beta would and that it's more penetrative so it can travel through the body better,

Reply 1693

BecauseFP

2

Original post by Elcor

What did people say for advantages of beta over gamma? I said beta is more short-ranged so it's more damaging to the patient, and a smaller proportion of the radiation leaves the body and is detected.

Gamma is less ionising because it' smaller and won't hit anything.
Gamma is better because it will penetrate stuff like hip replacements, unlike beta.

Also, for the energy released by the decay question, I kinda blanked and just said that the weak nuclear force does work, giving the electron kinetic energy, so energy has been released, thoughts?

Reply 1694

chem@uni

9

Original post by leroythelost

Damn it, I felt good just after the exam then I come here to find out I lost a lot of stupid marks...I need a high A in this for an A in physics but i doubt ill even get an A in this paper

What do people reckon about 135-140ums is in marks for this paper.

88 ish

Posted from TSR Mobile

Reply 1695

Alex621

17

Original post by Hummi_C

It gave you the distance, 1.8 m and the terminal velocity (call it v, I can't remember its value) therefore time = d/s = 1.8/v.

You calculated the force in the previous question, and since a = F/m and you're given the mass you can calculate the acceleration.

Then use SUVAT from AS to find s (horizontal displacement):

s=ut+1/2at^2

(I think)

I was going to do that but then I thought it wouldn't be travelling at terminal velocity straight away? Or did the question say it started at terminal velocity. Either way I ended up with 0.5cm whereas everyone else got 5cm

Reply 1696

leroythelost

10

Original post by chem@uni

88 ish

Posted from TSR Mobile

I love how you said that just after I finished working out I got about 78 in this paper..Thank anyway.

Reply 1697

Hummi_C

14

Original post by AlexParmenter

I was going to do that but then I thought it wouldn't be travelling at terminal velocity straight away? Or did the question say it started at terminal velocity. Either way I ended up with 0.5cm whereas everyone else got 5cm