Got everything right except for the graph, didnt make it insersect, i also didnt write the full bearing for the last question, other than that i thibk i got it all, how many marks do you think i dropped and the ums with it?

Reply 26

thegeorgesmith

Original post by kprime2

I think they should be under 60 for an A. 65 should be 90 at least. 60 should be a low A

What would happen if say you got 50 on the first paper and 70 on the second paper? Do they come together to create one grade or can you count the grade on the one that got higher marks?

Reply 27

kprime2

Original post by thegeorgesmith

What would happen if say you got 50 on the first paper and 70 on the second paper? Do they come together to create one grade or can you count the grade on the one that got higher marks?

Are you referring to retakes?

Reply 28

TheRandomGenius

Do you reckon 73 is 100UMS, @kprime2? Also where do you find the 100UMS boundary for previous papers?

Reply 29

kprime2

Original post by TheRandomGenius

Do you reckon 73 is 100UMS, @kprime2? Also where do you find the 100UMS boundary for previous papers?

Yeah should be. This paper should be below 60 for an A, so even if it's 59 then 71+ would be full UMS. I found it from the Edexcel mark converted on their website.

Reply 30

kprime2

Original post by metrize

The graph has to intersect twice, the second intersection is at (40,0). If you missed out the first intersection I'd guess that's one mark lost.

For the last question, you don't HAVE to write the direction as a bearing. Anything along the lines of '45 degrees below the horizontal' or 'south west' or a diagram with an arrow and the angle would be accepted. It's one mark for direction. So probably dropped 2 marks. 73/75 100 UMS. Even if at worse you dropped 3 marks then 72/75 should still be 100 UMS

Reply 31

philo-jitsu

pretty sure i got 55.....would this be enough to scrape a B?

Reply 32

yby

Original post by kprime2

Trickier than usual. Hell lot of simultaneous equations seems to be the trend in some of these recent papers.

q3, q6 and 7a will probably be answered poorly.

https://drive.google.com/open?id=0B3xSC6XqSy7kR3dhWDRkRGx0eFk

My answers using g have been given to 3sf. 2sf of course is also accepted.

(just a heads up, I will be posting answers to C3, C4 and some of the other modules too)

kprime2 the great, thanks.

Reply 33

fpmaniac

Oh my goooooooood. For the uniform rod question, I picked the wrong reaction force to be 0.... How many marks will i get for that

Reply 34

fpmaniac

Also, for the impulse question, I worked out the resultant force after working out the friction and acceleration. Would that be right

Reply 35

metrize

Original post by kprime2

Great, I hope I didn't make some other little error with sig figs or something, thanks a lot for the model answers

Reply 36

iamshavonn

****!!!!!! I just realized that I did everything right for the slope question, but because I forgot the component of weight acting downwards, my answer at the end is wrong. How many marks do you think I will get for a perfect method, and component diagram? :/

Reply 37

Reesharr

Original post by kprime2

15N to 2sf is still correct. Answers involving g should in fact be rounded to 2sf but they also accept 3sf. Full raw well done

I take it you're a physicist then. :smile:

In my role as a mathematician I'd stick with 3sf. This is because in maths we talk about 30° and 45° but we don't mean the former to 1sf and the latter to 2sf. We have this concept of exactness. So if I'm told that g = 9.8 (when I was young, it was always 9.81) then that's 9.8 precisely. The exam paper doesn't say 9.8 to 2sf.

However, as an engineer (which is what I actually am - CEng, MIET) I fully understand that the real world is imprecise. And I've had some great conversations in the staff room with my physics colleagues about how we might normalise how we teach things like mechanics in physics v in maths.

I personally simply warn my maths students that there is a difference in approach and explain why! :biggrin:

Edit: Sorry I should make clear that I totally agree with you that Edexcel are quite relaxed about 2sf v 3sf on calculations involving g - but always remember to round at the end!

(edited 7 years ago)

Reply 38

Reesharr

Original post by fpmaniac

Also, for the impulse question, I worked out the resultant force after working out the friction and acceleration. Would that be right

Yes, that's how I would have done it.

v² = u² + 2as --> 0 = u² - 2a x 5 (as a is deceleration) to get u² = 10a

F = μR = mg/8 (where m = 0.4 as I know it's going to cancel out in a moment)

F = ma --> mg/8 = ma, so a = g/8

Hence u² = 10g/8 = 49/4 --> u = 7/2 = 3.5

And finally I = (4 + 3.5) x 0.4 = 3Ns.

(edited 7 years ago)

Reply 39

Reesharr

Original post by kprime2

I'm not sure I agree. The sketch question (part (a)) comes before the information given for part (b) so technically it's perfectly possible for the graphs not to intersect. Eg T could be very close to 25 secs. But I'm happy for you to prove me wrong! :smile:

(edited 7 years ago)