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# M2 Centre of mass watch

1. A uniform wire of length 6m is bent to form a triangle ABC where AB is 1.5m and BC is 2.5m. Calculate the distnace of the centre of mass of the triangle (a) from AB (b) from AC.

Can some one do this and go through it for me? Im really lost when it comes to centre of mass...
2. finding centres of mass is basically all about finding the point in an object where the moments would be the same if all the weight of the object acted at that point. so essentially you have totake the three sides seperately, and calculate their moments about an axis (AB for part (i) and AC for part (ii)), and then find a point that will have the same moment if the weight of the whole triangle acted at that point.
3. Elpaw, 10 days to what?
4. (Original post by bono)
Elpaw, 10 days to what?
i'm not sure but are poland joining the EU in 10 days? they are at some point.
5. (Original post by Ollie)
i'm not sure but are poland joining the EU in 10 days? they are at some point.
Ahhhh, that would explain his avatar then!
6. (Original post by elpaw)
finding centres of mass is basically all about finding the point in an object where the moments would be the same if all the weight of the object acted at that point. so essentially you have totake the three sides seperately, and calculate their moments about an axis (AB for part (i) and AC for part (ii)), and then find a point that will have the same moment if the weight of the whole triangle acted at that point.
Ive tried it, got it wrong, and dont really understand the concept very well. Can you go through it for me please?
7. (Original post by imasillynarb)
Ive tried it, got it wrong, and dont really understand the concept very well. Can you go through it for me please?
If you drew a diagram of some sort, i may be able to help you. i've done M1 Centres of Mass (my syllabus), although M2 Centres of mas on yours may be harder.

A diagram may be good.
8. (Original post by bono)
If you drew a diagram of some sort, i may be able to help you. i've done M1 Centres of Mass (my syllabus), although M2 Centres of mas on yours may be harder.

A diagram may be good.
Theres no diagram. Thats what I got given^^.

For example, one of the examples in the book says exactly what you said. But the hypotenuse of the triangle is 13, yet they say the midpoint of that line is 6? Im confused, why is this?

Ahar, Ive also just noticed something that I havent before. Ill try again..
9. Done it, was bloody easy once I read the question
10. (Original post by imasillynarb)
Done it, was bloody easy once I read the question
Good.

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