Recent content by pugtm

Homework Statement i'm having trouble coming up with an equation for this problem [/B] Mulder and Scully agree to meet at the FBI lobby sometime within a period of N minutes (e.g. 40 minutes). Each of them may show up anytime during that period (with a uniform distribution). If Scully arrives...

Homework Statement For a following differential equation d^2y/dx^2-4y=(e^x)/x  Find the solution using numerical methods Homework Equations d^2y/dx^2-4y=(e^x)/x The Attempt at a Solution %num dx=0.01; x=1:dx:3; l=zeros(1,length(x)); m=zeros(1,length(x)); l(1)=1; m(1)=0.25; for...

Homework Statement x=2y^2 x=0 y=+-6 rotated around y Homework Equations integral 2pi*x(f(x)dxThe Attempt at a Solution integral from -6 to 6 of 2pi*y*2y^2 dy but i get something far less than the correct answer

thank you all for your timely assistance

the new integral is int 2tan(x)sec(x)^2/Sqrt(4tan(x)^2+4) the sec^2 cancel out making it the integral of 2tan(x)=-2lncos(x)

how do you get rid of the natural log at the end?

Homework Statement \int x/sqrt{(x^{2}+4)} Homework Equations x=2tanx The Attempt at a Solution x=2tanx \int2tan\vartheta/\sqrt{tan^2\vartheta}+4 2/2 *\inttan/sec \intsin=-cos now is the part where i am stuck i know from using substitution that the answr should be...

thanks all, what are the equations for the work function and threshold wavelength though?

Homework Statement When light of wavelength 298 nm is incident on potassium, the emitted electrons have maximum kinetic energy of 1.65 eV. A)What is the energy of an incident photon? The value of h c is 1240 eV · nm . Answer in units of eV. B)What is the work function for potassium? Answer in...

my thanks, did you get 3.170605653e-6 as the final answer by any chance?

yes, essentially so don't i need to slice it in order to get all the surface area's so i don't get where you are getting r in regards to X from when the integral is dL

i'm not sure how you can rotate the circle and get the spheroid. it's sphere with semi spheres cut off of the edges... so i fail to see how rotating the bounded circle would produce this shape. so like slicing off both the ends of an onion. maybe I'm not understanding what you mean.

sorry i don't understand how you achieved the A(L) also is L the length of the width of the sphere or the radius of the cross sections?

Homework Statement a resistor of a solid sphere of radius R=.75 cm and is made of a material of resistivity\rho=6.8e-8\Omegam. the sphere is sliced on either side vertically so that the horizontal diameter is equal to R. if the current is flowing from left to right what is the objects...

thanks yeah i got it