ssel17
Badges: 1
Rep:
?
#1
Report Thread starter 5 years ago
#1
I am practicing for the PHYA2 paper on thursday and due to completing almost all the available past papers I have begun trying out some legacy papers. Now this particular one is PA02 JAN09. This is the question:
http://www.egsphysics.co.uk/files/a_...W-MS-JAN09.PDF and this is the mark scheme: http://www.egsphysics.co.uk/files/a_...W-MS-JAN09.PDF
The question is: by taking moments about B find the magnitude of P.
Now I don't necessarily want to know how to answer this, more if we should be able to answer this question as part of our specification? I find that many of the questions in the legacy papers are impossible to answer with our knowlege as of course much of the spec changed. Therefore even after looking at the markscheme for this I was really stuck. Should I be able to answer this? If so, tell me how, but if not then fab!
This is the question sorry! https://scontent-lhr3-1.xx.fbcdn.net...08&oe=556E7581
0
reply
TSR Jessica
Badges: 19
Rep:
?
#2
Report 5 years ago
#2
Sorry you've not had any responses about this. Are you sure you’ve posted in the right place? Posting in the specific Study Help forum should help get responses.

I'm going to quote in She-Ra now so she can move your thread to the right place if it's needed. :yy:

Spoiler:
Show
(Original post by She-Ra)
x
0
reply
She-Ra
Badges: 21
Rep:
?
#3
Report 5 years ago
#3
(Original post by ssel17)
I am practicing for the PHYA2 paper on thursday and due to completing almost all the available past papers I have begun trying out some legacy papers. Now this particular one is PA02 JAN09. This is the question:
http://www.egsphysics.co.uk/files/a_...W-MS-JAN09.PDF and this is the mark scheme: http://www.egsphysics.co.uk/files/a_...W-MS-JAN09.PDF
The question is: by taking moments about B find the magnitude of P.
Now I don't necessarily want to know how to answer this, more if we should be able to answer this question as part of our specification? I find that many of the questions in the legacy papers are impossible to answer with our knowlege as of course much of the spec changed. Therefore even after looking at the markscheme for this I was really stuck. Should I be able to answer this? If so, tell me how, but if not then fab!
This is the question sorry! https://scontent-lhr3-1.xx.fbcdn.net...08&oe=556E7581
Moved this to the physics exam forum
0
reply
ssel17
Badges: 1
Rep:
?
#4
Report Thread starter 5 years ago
#4
Thank you!
0
reply
oonic0rn
Badges: 2
Rep:
?
#5
Report 5 years ago
#5
http://filestore.aqa.org.uk/subjects...2-QP-JAN13.PDF

could anyone explain why in question 3 b ii the tension is acting as an anti-clockwise moment? normally good with the moment stuff but i thought way too deeply into it trying to make a triangle as the tension is acting to the left which doesn't strike me as anticlockwise. thanks!
0
reply
ssel17
Badges: 1
Rep:
?
#6
Report Thread starter 5 years ago
#6
(Original post by oonic0rn)
http://filestore.aqa.org.uk/subjects...2-QP-JAN13.PDF

could anyone explain why in question 3 b ii the tension is acting as an anti-clockwise moment? normally good with the moment stuff but i thought way too deeply into it trying to make a triangle as the tension is acting to the left which doesn't strike me as anticlockwise. thanks!
Even though it's acting to the left, the brake cable would pull the hole it's attached to towards the left, which if you imagine with that arrangement, would pull the bar anti clockwise about the pivot. I usually just try to imagine which way the body would move by placing my finger on the chosen pivot. In this case, you can see that pulling left above the pivot would turn the brake anticlockwise about it.
Sorry if that's an awful description ahaha.
1
reply
oonic0rn
Badges: 2
Rep:
?
#7
Report 5 years ago
#7
(Original post by ssel17)
Even though it's acting to the left, the brake cable would pull the hole it's attached to towards the left, which if you imagine with that arrangement, would pull the bar anti clockwise about the pivot. I usually just try to imagine which way the body would move by placing my finger on the chosen pivot. In this case, you can see that pulling left above the pivot would turn the brake anticlockwise about it.
Sorry if that's an awful description ahaha.
No thats great, thankyou!
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Which of these would you use to help with making uni decisions?

Webinars (65)
12.17%
Virtual campus tours/open days (129)
24.16%
Live streaming events (46)
8.61%
Online AMAs/guest lectures (52)
9.74%
A uni comparison tool (124)
23.22%
An in-person event when available (118)
22.1%

Watched Threads

View All