Recent content by ABoul

Homework Statement "A polymer, with Young’s modulus 2GPa and yield stress 50MPa, is reinforced by uniaxially aligned glass fibres which have Young’s modulus 70GPa and fracture at 1400MPa. The volume fraction of fibres is 40%. (a) Calculate Young’s modulus for the composite in the...

i see. so the total hydrostatic pressure is the sum of all components, and that's where the factor of 3 comes in, right?

Homework Statement derive the equation for the bulk modulus, K = E/3(1 - 2v), where v is poisson's ratio. Homework Equations E = stress/e, where e is strain The Attempt at a Solution e_v = e_x + e_y + e_z e_y = e_z = -v*e_x e_v = (1 - 2v)*e_x K = stress/e_v therefore K =...

but each mass is connected to 2 springs. therefore each equation should only have 2 terms. the only mistake i can see with the second equation is that Fx2 (force from the THIRD spring) should be negative. oh, and sorry if i haven't been clear enough -- the diagram goes like this: [wall]...

i did. there are only 2 displacements (x1 and x2), right? the extension of the third spring is not kx2?

Homework Statement 2 equal masses are joined together by a spring of stiffness k. each of the masses is then connected to a wall with an identical spring. derive the equations of motion in matrix form. (a diagam has 2 masses with x1 on top of the first mass and x2 on top of the second.)...

so B is constant anywhere inside the solenoid? that would make sense because the magnetic field is roughly a straight line when inside the solenoid as I've drawn it, but i still fail to see how the ratio of the length of the solenid and its diameter make a difference. also, is there a difference...

Homework Statement the question can be found here: http://www.mailfreeonline.com/uploader/CED0D65C.jpg Homework Equations ampere's law The Attempt at a Solution a. (is B the magnetic field?) B = uI/L; u = 4pi x 10^-7, I = 1, L = 2pi x 0.1 so B = 2 x 10^-6 ^ can anyone...

Homework Statement the question can be found here: http://www.mailfreeonline.com/uploader/5731C3EE.jpg Homework Equations The Attempt at a Solution i couldn't do parts a and b. part c: i added resistors in parallel and somehow got a value that Vo = 9.33V (part of the circuit...

ah thansk for that. I'm just waiting to see your circuit (it's still being approved).

if you substitute in my (supposedly correct) equations for i1, i2 and i3, you don't reach the conclusion that V1 = V2 = V3... also, using the window method, I'm sure you can inspect every window individuall. i just don't know how to do it lol.

also, isn't it true that i1 + i2 = i3? if you plug in my values, you get something else.

ah i see what you mean now. so where did i go wrong? i thought my KVL logic was correct...

hmm... what does that mean?

whoops sorry... it must have been a typo. how about part 3?