Recent content by fredrick08

is it 1370/(pi*R(Sun)^2/D(earth)^2)=2x10^7 Wm^-2st-1?

Homework Statement given that T(sun)=5771.4, S(Earth)=1370, D(Earth)=1.5x10^8km, R(sun)=7x10^5km calculate the radiance of solar radiation at Earth orbit Homework Equations Irradiance=Radiance/Solid Angle Solid Angle=Area/Distance^2 I=sigma*T^4 The Attempt at a Solution...

oh sorry i got the temperature conversions wrong.. K-273 not 273-K

Homework Statement If the Earth's average cloud cover increased, what effect would it have on the albedo temperature? If the Earths albedo increased to 0.32, what would be the average temperature? Ok I thought that if the albedo was higher, it would reflect more light, thus coolign would...

anyone?

Homework Statement Let us consider an approximation to an integral. Let f(x) be some continuous function on [a, b]. We wish to find an approximation for the integral I = int from a to b of f(x)dx in the following manner: Subdivide the interval into N intervals of length h = (b−a)/N. Let xi...

or does anyone know the average size of e-beams?

Homework Statement Does anyone know a method or calculation, that can calculate the size of an e-beam? I made a 40 square micron pattern, in approximately 30 seconds with 5pA current if this helps... I have no idea how to estimate the size of the beam tho.

anyone?

ok i can work backwards form the answer, and see that is is correct... but i don't know how to show Ux and Vx from what i have got.

Homework Statement x=r*cos(theta) y=r*sin(theta) Ur=Ux*cos(theta)+Uy*sin(theta) Utheta=-Ux*r*sin(theta)+Uy*r*cos(theta) Vr=Vx*cos(theta)+Vy*sin(theta) Vtheta=Vy*r*sin(theta)+Vx*r*cos(theta) cauchy rieman equations, Ux=Vy Uy=-Vx and for polar Ur=(Vtheta)1/r Vr=(Utheta)(-1/r) show that...

ok for the x^2 and y^2 values, i subbed in there respecful values x=rcos(theta) y=rsin(theta) then i get... 1+(sin(\theta)/sqrt(1-cos^2(\theta)/r^2))=1+(cos(\theta)/sqrt(1-sin^2(\theta)/r^2)), which clearly does no equal?

ok so if i do the chain rule that elib gave... i get (1/cos(theta))*cos(theta)+-1/(r*sqrt(1-x^2/r^2)*-rsin(theta)... but when i do dv/dy i kind of get similar answer, but instead of the x^2 its y^2, and the last term is cos(theta) and not sin(theta)

do i rearrange?? coz r=x/cos(theta)?? then diffrentiate with respect to x?

ok then, but can i ask how do u do dr/dx and dtheta/dx? since r and theta are part of x?