Recent content by jesuslovesu

Homework Statement I am in the process of doing a physics problem with a differential equation that has the form: y = Acos(kx) + Bsin(kx) According to my notes, this can also be written as y =Aejkx + Be-jkx, unfortunately I just don't see how to write the original equation like that...

Homework Statement Supopse that a 100 W source radiates light of wavelength 600 nm in all directions and that the eye can detect this light if only 20 photons per second enter a dark adapted eye having a 7 mm diameter pupil. How far from the source can the light be detected under these...

Homework Statement A gun is fired straight up. Assume a quadratic drag force. Show (upward motion) v^2 = Ae^{-2kx} - \frac{g}{k} (downward motion) v^2 = g/k - Be^{2kx} Homework Equations The Attempt at a Solution I can easily solve the integrals unfortunately I am having difficulty setting...

Ok got it thanks.

Homework Statement Use the scalar projection to show that a distance from a point P(x1, y1) to the line ax + by + c = 0 is \frac{ax1 + by1 + c}{\sqrt{a^2 + b^2}}Homework Equations scalar projection = \frac{a . b}{|a|} The Attempt at a Solution The first thing that I did was to say that b =...

Internships/Coops Hey guys, I will most likely have the opportunity to get an internship or co-op at my father's place of work. Unfortunately, what the engineers do there has nothing to do with what I would actually like to do. My question is would this affect me negatively if I were to get an...

Homework Statement A = (1,1,-2) C = (0,1,-5) (in cartesian coordinates) Let A and C be drawn from a common origin and let C rotate about A with an angular velocity of 2 rad/s. Find the velocity of the head of C. Homework Equations v = w x r The Attempt at a Solution w = 2...

[SOLVED] Laplace Transform Homework Statement Suppose F(s) = \displaystyle\mathcal{L}(f(t)) Show that \displaystyle\mathcal{L}(f(ct)) = 1/c F(s/c) Homework Equations The Attempt at a Solution \displaystyle\mathcal{L}(f(t)) = \int_0^{inf} e^{-st} f(t) dt \displaystyle\mathcal{L}(f(ct)) =...

got it now thanks, those steps are really handy

Unfortunately I haven't studied complex analysis. I made an error in my original post (and I can't edit it for some reason) It's now worse than before s^2 + s - 2 = (s+2)(s-1) -\frac{e^{-2s}}{3(s+2)} + \frac{e^{-2s}}{3(s-1)} I see the time shift equation on wikipedia, but since the 's' is in...

[SOLVED] Laplace transform Homework Statement Find the inverse laplace transform of \frac{e^{-2s} }{s^2 + s - 2} Homework Equations The Attempt at a Solution I'm able to do about half of the problem using partial fractions, I've found...

[SOLVED] Trig Question Homework Statement Let's say I have tan(2\theta) = cot(\phi) I'm not quite sure how to simplify it (I want to solve for theta) I could say tan(2\theta) = 1 / tan(\phi) 2\theta = atan( 1 / tan(\phi) ) but then I'm not sure what to do after that. Do I take the atan of 1...

Oh my bad, sorry yes, theta is the angle of the ball's velocity and phi is the angle of the incline.

Homework Statement The three vectors A, B, C point from the origin O to the three corners of a triangle. Show that the area of a triangle = 1/2 |( BxC + CxA + AxB )| Homework Equations 1/2 |a x b| = 1/2 |a||b|sin(alpha) The Attempt at a Solution My initial attempt at this...

[SOLVED] Horizontal Range (with incline) Homework Statement A ball is thrown up an (v0) incline. The ball is thrown at an angle phi from the incline and the incline has an angle theta with the ground. 1) Show the ball lands a distance R = 2{v_0}^2 sin\theta cos(\theta + \phi ) / (gcos{\phi...