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General Physics Question about a certain type of problem?
Hey all you einsteins,
I'm stuck on a problem and I do not understand why when sum of all forces for component X it is wSIN(theta) and sum for all components Y is wCOS(theta) instead of the usual cos for X and sin for Y.
The problem is specific when the situation is for something on a slant.
Please explain? I hope i made myself clear.. sorry for the misunderstanding if you didn't understand me.
1 Answer
- ?Lv 71 decade agoFavorite Answer
On a piece of graph paper, start with the standard X & Y axes and from the origin draw a right triangle with an x-side = +3 units and a y-side = +4 units, and from the origin draw the hypotenuse of this triangle = 5 units.
Call angle between x-side (3 units long) and the hypotenuse (5 units long) = Θ {theta}
Call angle between y-side (4 units long) and the hypotenuse (5 units long) = α {alpha}
length of x = (5)(sin Θ) = 3 = (5)(cos α)
length of y = (5)(cos Θ) = 4 = (5)(sin α)
So the same side of the triangle can be related to the sin or cos function depending on which complimentary angle theta or alpha is referred to.
Hope this helps.