- #1
CinderBlockFist
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- 0
Guys, I am stuck on this problem. I have the answer from the back of the book, but I don't know how to solve it. I tried to solve it by isolating Ux, Vy, and trying to solve it by simultaneous equations, but I always end up getting something like Vy = Vy , or something like Vy - Vy = 0. It keeps going in circles, maybe this isn't the way to go. But anyways, this is the problem:
(note: the x, y , and z are written as small sub next to the U, V, and W, I just can't type it like it is in the book)
The three vectors
U = Uxi + 3j + 2k
V = -3i + Vyj + 3k
W = -2i + 4j + Wzk
are mutually perpendicular. Use the dot product to determine the compnents of Ux, Vy, and Wz.
The answers in the back of the book are Ux = 2.857, Vy = 0.857, Wz = -3.143.
I am using the dot product definition: U dot V = UxVx+UyVy+UzVz
so I get (Ux)(-3)+(3)(Vy)+(2)(3) = 0
I set it all to zero because they are perpendicular to each other.
So simplifying for Ux, i get Ux = Vy + 2. THen I plug Vy +2 for Ux, but then I go in circles from there.
(note: the x, y , and z are written as small sub next to the U, V, and W, I just can't type it like it is in the book)
The three vectors
U = Uxi + 3j + 2k
V = -3i + Vyj + 3k
W = -2i + 4j + Wzk
are mutually perpendicular. Use the dot product to determine the compnents of Ux, Vy, and Wz.
The answers in the back of the book are Ux = 2.857, Vy = 0.857, Wz = -3.143.
I am using the dot product definition: U dot V = UxVx+UyVy+UzVz
so I get (Ux)(-3)+(3)(Vy)+(2)(3) = 0
I set it all to zero because they are perpendicular to each other.
So simplifying for Ux, i get Ux = Vy + 2. THen I plug Vy +2 for Ux, but then I go in circles from there.