Recent content by dan38

If I had a sphere centred at the origin with x > 0, y > 0 and z > 0 Would the angle boundaries be: 0 < θ < pi/2 0 < α < pi/2 ?

How do you know it's "k" and not negative "k"

S is a portion of a curve with r(u,v) where 0 < u < 2 and 0 < v < 2pi I'm meant to calculate Flux of the vector field F My Calculations First found dr/du then dr/dv Using the cross product, I found N = (- u cos (v) + 5 sin (v), -5 cos (v) - u sin(v), u) Then I dot product with the given...

Do either of these actions impact upon the elastic modulus? I can't think of any reason why they would, but just want to make sure. Thanks.

Well the sample vectors came from the differential equation And I already know how I can use that to find the field lines But the question says to sketch and hence find the field lines, so I thought this way wouldn't be allowed.. :/

Well just the shape made it look like parabolas when I joined the dots... I know that the vectors that I have plotted for each point is the curve's tangent vector. And that the curve is defined by the position vector r(t) Is there something else I'm missing?

Well they look like parabolas becoming wider as I progress down the y-axis... so dy/dx = ax and y = ax^/2 + c How do I find the variable "a"?

Basically I've been given a vector equation, V(x,y) and different points to draw the vector field with directional arrows at each point. The question seems to indicate that by sketching the field lines passing through these points I should be able to find the associated differential equation...

Homework Statement Is it possible to find the vector field line expression without the use of differential equations? Say I've sketched the field and found the shape to be parabolas, how would I find the general expression by just using the points I've been given?Homework Equations The Attempt...

ah I see, thanks!

oh yeah, sorry was a typo but anyway, the solutions say the answer is (10u,10v,−4u+2v+1.6) which isn't equivalent to my answer...

Homework Statement Plane: 4x−2y+10z =16. Homework Equations The Attempt at a Solution So I've used two parameters, "u" and "v" with x = u and y = v Re-arranging z in terms of "u" and "v": z = 1.6 - 0.4x + 0.2y Hence r(t) = (u , v , 1.6 - 0.4 x + 0.2y) Is this correct?

oh yeah lol, its final minus initial so my answer should be positive 4 right?

Homework Statement Find the work done by a force acting in the direction 2i - 5j + k in moving a particle from (3, 3, 1) to (1, 2, 4). Homework Equations The Attempt at a Solution I just found the displacement vector (2,1,-3) and did the dot product with the force vector...

hmm but how do I convert the string's movement to a torque acting on the wheel? (Given that I only know it's acceleration)