question.. (1 Viewer)

[Wohzazz]

wogboy, can you explain how to use the triangle method, i haven't seen it before

 

[Constip8edSkunk]

lol wog boy beat me to it

edit: triangle method is just trigonometry

 

[Ragerunner]

Constip8edSkunk.....I have no idea what you just did LOL.

I think I'll just use Wogboy's one hahah

 

[Wohzazz]

Originally posted by Constip8edSkunk
lol wog boy beat me to it

edit: triangle method is just trigonometry

trig? you mean you find all the vectors of the forces, then you find the resultant vector by treating them like lengths?

 

[wogboy]

you mean you find all the vectors of the forces, then you find the resultant vector by treating them like lengths?

Absolutely right.

 

[Constip8edSkunk]

lol rage, wogboy's was a summarised version of mine. just a point, shouldnt the 'd' in F3 be 0.02*sqrt2 m as the distance between B and D is not 0.02m

as for adding the vectors, from the diagram you can see that the vertical components of F1 and F2's cancel out. F3 is deducted from the aggregate horizontal component of F1 and F2 to find the net force.

to find the horizontal component of F1 (which is the same in F2), draw a triangle with F1 as the hypotenus. the angle btween that and the horizontal component('x') is 45 degrees as the wires form a square. so x=F1*cos pi/4

 

[Wohzazz]

how does the direction of the current affect the resultant force on D? that does change the way you add the vectors right?
also, when you mean vertical component what do you mean? and how does the horizontal component cancel?

also, isn't length BD 0.02squared, thus d=0.02^2

 

[wogboy]

how does the direction of the current affect the resultant force on D?

If you have two parallel wires with current travelling in the SAME direction, the two wires to ATTRACT. If the current in one of the wires goes in the OPPOSITE direction to the other, the wires will REPEL. So if you change the direction of the current in a wire, one (or possibly more) of the force vectors will be reversed in direction so your vector sum will be different.

that does change the way you add the vectors right?

The method you use to add vectors is always the same, it's just that some of the vectors will now point the other way.

also, isn't length BD 0.02squared, thus d=0.02^2

No it's 0.02*sqrt(2) metres, use Pythagoras' theorem.

 

[Xayma]

Originally posted by wogboy
No it's 0.02*sqrt(2) metres, use Pythagoras' theorem.

isnt it 0.02sqrt(8) metres???

 

[Constip8edSkunk]

its sqrt0.0008m = 0.02*sqrt2 m

 

[:: ck ::]

hrm ... wot book is this from =\

 

[Ragerunner]

My friend asked me this. And she got it from her teacher.

But yeah, crazy question

 

[Wohzazz]

ok call me dumb, but i still don't get how d=0.02 sqrt(r)
considering AD and AB and hypotenuse DB
ADsquared + AB squared equals DB squared
so 0.02squared + 0.02 squared equals DB sqaured
DB equal root 8^10^-4= some value but not sqrt0.02

tell me..am i stupid, i'll gracefully admit it

 

[Xayma]

Originally posted by Constip8edSkunk
its sqrt0.0008m = 0.02*sqrt2 m

Thats where I was going wrong, hits calculator... ahh that feels better.