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i dont get the wording of this question

hgujmn
humungus wot.png97.0KB

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Original post by KloppOClock
hgujmn


2(iii)?

What don't you get?
Original post by Kvothe the Arcane
2(iii)?

What don't you get?


"Calculate the distance from AD of the centre of mass of the frame"

what does that mean, its just words, doesnt make any sense
Original post by KloppOClock
"Calculate the distance from AD of the centre of mass of the frame"

what does that mean, its just words, doesnt make any sense


The vertical (perpendicular) distance. The distance from a point (centre of mass) to a line is always the shortest distance.
Original post by Kvothe the Arcane
The vertical (perpendicular) distance. The distance from a point (centre of mass) to a line is always the shortest distance.


yes i know that but i dont get what the question is asking, is it asking for the shortest distance between the centre of mass and any point along ad?
Reply 5
Avatar for meaty123
meaty123
Original post by Kvothe the Arcane
The vertical (perpendicular) distance. The distance from a point (centre of mass) to a line is always the shortest distance.


Original post by KloppOClock
yes i know that but i dont get what the question is asking, is it asking for the shortest distance between the centre of mass and any point along ad?




Yes fam, it is asking for the shortest distance.
Original post by meaty123


Yes fam, it is asking for the shortest distance.


question still doesnt make sense
get off ur high horse
Reply 7
Avatar for Zacken
Zacken
22
Original post by KloppOClock
question still doesnt make sense
get off ur high horse


From the centre of mass, drop a line down to AD that is perpendicular to AD. What is the length of this line?
Original post by KloppOClock
question still doesnt make sense
get off ur high horse


Yes it does. If you've learnt centre of mass you should be familiar with the way they word these types of questions. If you imagine AD as the x-axis, and AB as the y-axis (origin at A), you're simply finding the y-coordinate of the centre of mass, which is a perpendicular distance to AD.
Original post by RDKGames
Yes it does. If you've learnt centre of mass you should be familiar with the way they word these types of questions. If you imagine AD as the x-axis, and AB as the y-axis (origin at A), you're simply finding the y-coordinate of the centre of mass, which is a perpendicular distance to AD.


im not familiar at all with the wording of these questions, also, the mark scheme starts chattin **** about vertical moments???
Original post by KloppOClock
im not familiar at all with the wording of these questions, also, the mark scheme starts chattin **** about vertical moments???


Yeah. That's how you work out the centre of mass. You work out the horizontal and vertical moments individually for their own 'co-ordinates' so to speak if we are still going by the x-y plane idea.
they want the vertical distance of the COM from line AD
Original post by RDKGames
Yeah. That's how you work out the centre of mass. You work out the horizontal and vertical moments individually for their own 'co-ordinates' so to speak if we are still going by the x-y plane idea.


well i knew how to do it, just not what it was called...

also when i did do it, i didnt get the right answer.
Reply 13
Avatar for Notnek
Notnek
21
Original post by KloppOClock
hgujmn

I assume there's more info somewhere for this question?

EDIT: Yes there is (page 6)
(edited 7 years ago)
Original post by notnek
I assume there's more info somewhere for this question?


no, i mean, am i meant to just assume its a lamina object thing? when i did i didnt get the right answer
Reply 15
Avatar for Notnek
Notnek
21
Original post by KloppOClock
no, i mean, am i meant to just assume its a lamina object thing? when i did i didnt get the right answer

Check the edit to my last post.
Original post by KloppOClock
well i knew how to do it, just not what it was called...

also when i did do it, i didnt get the right answer.


It's just X=∑mixi∑mi\displaystyle X=\frac{\sum m_ix_i}{\sum m_i}. And the 3 things are the lamina itself, E and F. You need to know their masses if you're going by this. Can be slightly different depending on the question.
(edited 7 years ago)
Original post by notnek
I assume there's more info somewhere for this question?

EDIT: Yes there is (page 6)


well that edit makes a whole lot more sense now.

this pic is all i had to work from, was I just meant to guess the masses?

thanks for helping and not being a condescending prick

*cough* @the bear *cough*
wot is this bullshit.png163.0KB
Reply 18
Avatar for Notnek
Notnek
21
Original post by KloppOClock
well that edit makes a whole lot more sense now.

this pic is all i had to work from, was I just meant to guess the masses?

thanks for helping and not being a condescending prick

*cough* @the bear *cough*

The creator of the worksheet must have forgotten to add the information.
This is why I don't do Maths.

I just spent like 5 minutes thinking "But that's not a cone... How can it topple if its a bloody rectangle?"

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