Answer to Question #254363 in Mechanics | Relativity for Neil

Question

The tension in the supporting cable AB is T = 425 N. Write the tension as a vector (a) as its acts on point A and (b) as it acts on point B. Assume a value of ø = 30°

Answer 1

I started by finding the AB→ which I used A = (0, 5cos(30), 5sin(30)) and B = (2, 0, 6), which gave me AB→ = <2, -4.33, 3.5>.

Next I used n→ = (AB→) / (||AB→||) to find n→ = <.338, -.732, .5916>

Then I found T→ = (T)(n→) = <143.65, -311.1, 251.43>

θ is in the x-y (azimuthal) plane, so it should not apply directly to the z-coordinate as one did for the coordinates of A, necessarily. One needs to think in terms of two angles, poloidal and azimuthal. Note point B is offset from the polar axis.