# Calculate scalar H number divided by N vector?

Posted 1 month ago
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 Hello. I am trying to calculate the vector X as shown in the attached file. But I don't know what commands to use. Can you give me information about this? Attachments:
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Posted 1 month ago
 1) N is a Mathematica-Symbol. Look it up in the Help-Section. You shouldn't use N, try vN or so.2) Your "N" clearly is a vector of dimension 3. But your H is a scalar. Tell me , why shouldscalar / vector an operation that is - at least - not well (if not far from ) defined be a vector? Did you mean N / H ?
Posted 1 month ago
Posted 1 month ago
Posted 1 month ago
 First of all, thank you for your reply. There are vectors N and X such that = H. Actually, I'm trying to find the possible values of the X vector. How do I calculate with Mathematica?
Posted 1 month ago
 I think you mean this( < vecN , vecX > = H = prod in this code ) vecN = {a, b, c}; vecX = {x1, x2, x3}; scalar = s; prod = vecN.vecX; lsg=Solve[prod == scalar, x1] // Flatten Then x1 is given as function of x2 and x3. Chose any x2 and x3, calculate x1 and this vector gives your condition. vecX1 = vecX /. lsg vecN.vecX1 
Posted 1 month ago
 These are exactly the codes I'm looking for. Thank you very much for your help.
Posted 1 month ago
 Can we divide two vectors? Can we divide two vector quantities? For eg., Pressure( a scalar) equals force (a vector) divided by area (a vector).
 No. There is not an operation like vector / vector. By the way, pressure in general is NOT a scalar, but a Tensor: press = { {pxx, pxy, pxz}, {pyx, pyy, pyz}, {pzx, pzy, pzz} }; and the force experienced by a surface ( given by a vector surf = { sx,sy, sz } is given by force = press.surf Often the off-diagonal elements of press are 0 (this is most likely not the case in vsicous fluids) , and if in addition the diagonal elements are equal = p ( an isotropic medium) the force points in the direction of surf. Then you can write p = Norm[ force ] / Norm[ surf ] press = { {p, 0, 0}, {0, p, 0}, {0, 0, p} }; f1 = press.{1, 1, 1} f2 = press.{2, 3, 4} Norm[f1]/Norm[{1, 1, 1}] Norm[f2]/Norm[{2, 3, 4}]