Recent content by checkmatechamp

I'm an engineering student with a part-time job at a deli (and a seasonal job in construction, but that's besides the point). To entertain my coworkers, I talk about the different forces/stresses present when slicing the meat. So for the sake of accuracy, let's say I have a cylindrical piece of...

Can somebody confirm if this is correct? I'm trying to use a wye-delta transformation on capacitors to solve for equivalent capacitance, but to be super-precise, I want to put capacitance in terms of resistance. I = C*(dV/dt) V = IR, so I = V/R V/R = C*(dV/dt) (V*dt) = R*C* dV Integrate both...

If you have say, a 3 story building and each floor has I beams (with cross pieces) carrying the weight, would the beam holding up the second floor have to carry the load of the third floor as well? I don't think so (if I drew my FBD correctly, the largest reaction should be the one pushed up by...

So you mean change the limits as follows? θ from 0 to 2π φ from 0 to π/3 ρ from secφ to 2

Homework Statement Find the flux of the field F(x) = <x,y,z> across the hemisphere x^2 + y^2 + z^2 = 4 above the plane z = 1, using both the Divergence Theorem and with flux integrals. (The plane is closing the surface) Homework Equations The Attempt at a Solution Obviously, the divergence...

Alright, let's see. 8t^2v' - 8tv = -v^3 v' - v*t^-1 = -v^3 / (8t^2) v^-3 * v' - v^-2 * t^-1 = -1 / (8t^2) Bernoulli form is v^-n * v' + p(t)*v^(1-n) = q(t) So that means n = 3 in this case. Use a substitution u = v^(1 - 3) u = v^-2 and u' = -2v^-3*v' So then substituting back in, we...

Homework Statement 8t^2 * y'' + (y')^3 = 8ty' , t > 0 Homework EquationsThe Attempt at a Solution I tried using the substitution v = y' to get: 8t^2 * v' + v^3 = 8tv I rewrote it in the form 8t^2 * dv/dt + v^3 = 8tv, and then moved the v^3 to the other side to get 8t^2 * dv/dt = 8tv - v^3...

Homework Statement ∑ x2n / n! The limits of the sum go from n = 0 to n = infinity Homework EquationsThe Attempt at a Solution So I take the limit as n approaches infinity of aa+1 / an. So that gives me: ((x2n+2) * (n!)) / ((x2n) * (n + 1)!) Canceling everything out gives me x2 / (n + 1)...

Homework Statement A mass weighing 16 lb stretches a spring 3 in. The mass is attached to a viscous damper with a damping constant of 2 lb-s/ft. If the mass is set in motion from its equilibrium position with a downward velocity of 2 in/s, find its position u at any time t. Assume the...

After some checking, I finally entered the answer y = 1.9*sin(2t) - 1.075*cos(2t) + 0.25t^2 - 0.125 + 1.2e^t. Thank you so much for your help! :)

Alright, so for the particular solution: yp = At^2 + Bt + C + De^t yp' = 2At + B + De^t yp'' = 2A + De^t 2A + De^t + 4(At^2 + Bt + C + De^t) = t^2 + 6e^t 2A + De^t + 4At^2 + 4Bt + 4C + De^t = t^2 + 6e^t So grouping the terms together, you get 4A = 1, so A = 0.25 De^t = 6e^t, so D = 6 2A +...

Homework Statement u'' + w20*u = cos(wt) w refers to omega. Homework EquationsThe Attempt at a Solution I'm not sure where to begin on this. For starters, it's a multiple choice problem, and all the answers are given in terms of y, so I'm not sure if u is supposed to replace y' or something...

Homework Statement y'' + 4y = t2 + 6et; y(0) = 0; y'(0) = 5 Homework Equations The Attempt at a Solution So, getting the general solution, we have r2 + 4 = 0, so r = +/- 2i So the general solution is yc = sin(2t) + cos(2t) I then used the method of undetermined coefficients to figure that...

Homework Statement dy/dx = x/(x2y + y3) Homework Equations The Attempt at a Solution The middle term is what's throwing me off. I can't put it in terms of y = vx (Dividing by x2 means that the y term gets screwed up. (It would turn it into yv2). Out of curiosity, I tried flat-out...

I thought I got this problem wrong, but I think I have it right now. It turned out that when I was taking the derivative of e^xy2with respect to y, I forgot that you're supposed to multiply by 2xy (the derivative of xy2), not just x. Homework Statement (y2* e^xy2 + 4x3 dx + (2xy * e^xy2 -...