Lami Rule and Triangle of forces statics

Avva · 2011-03-22 01:15:04

Three coplanar forces 8, 10 and 12 newtons act at a particle. If the forces are in equilibrium, What is the measure of the angle between

the two forces 10 and 12 newtons?

Thanks in Advance.

John E. Franklin · 2011-03-22 11:57:53

Cut all the numbers in half.
now u hav 4,5, n 6.
make a triangle with
sides 4,5,n 6. Find interior
angles with law of sines
or law of cosines. The
actual problems vectors
Will have the same angles
or slopes except connect
to a center point...

John E. Franklin · 2011-03-22 12:15:10

The vectors will all go clockwise around the triangle, that way, you start
at point A, where you end up after three sides, so nothing happens.
Then just move the three vectors so they stem out from the center point.
Or have them all push on the center point, either way, the point won't move.

John E. Franklin · 2011-03-22 12:18:56

Use the Law of Cosines to find the angle given three sides. It is on wikipedia.
The law of sines is too general I think; too many unknowns.

Avva · 2011-03-25 20:05:50

many thnx John I didn't know How I missed cosine law

Math Is Fun Forum

#1 2011-03-22 01:15:04

Lami Rule and Triangle of forces statics

#2 2011-03-22 11:57:53

Re: Lami Rule and Triangle of forces statics

#3 2011-03-22 12:15:10

Re: Lami Rule and Triangle of forces statics

#4 2011-03-22 12:18:56

Re: Lami Rule and Triangle of forces statics

#5 2011-03-25 20:05:50

Re: Lami Rule and Triangle of forces statics

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