Recent content by Smusko

I am sooooo stupid it's almost depressing. Thank you.

When you integrate that, what happes with v? v=0.9gt - cs? since ds/dt = v. It feels so wrong. Or do you treat v as a constant and v=0.9gt - cst? That also feels wrong.

Homework Statement A steel ball is released at the surface of the ocean and it takes 64 minutes for it to hit the bottom. The balls downward acceleration is a=0.9g-cv where g=9.82 m/s2 and c = 3.02s-1 and v is the speed. What is the depth of the ocean where the ball was released? Homework...

Dang, thought. Missed the ********* **** **** minus sign. I got sqrt(1-Sin2(t)) because (dz/dt) = -aSin(t). Thanks.

This is image is representative on how we think the universe looks on the largest scales. [PLAIN]http://upload.wikimedia.org/wikipedia/en/c/c0/Local_galaxy_filaments_2.gif from http://en.wikipedia.org/wiki/Galaxy_filament Looks pretty chaotic.

I do not officially know what I'm talking about, but here goes. Maybe theoretically they don't cover every possible infinitesimal change in frequency, but enough to show us that it follows a mathematically smooth probability curve. And when you get the spectrum of a star it comes with a...

I have checked with Wolfram on all the derivatives and integrals. The dS must be equal to a*cos(t)dt and if it is like you say that you put z=a*cos(t) and integrate from 0 to pi/2 then the integral should look like this: a2*Integral(cos2(t))dt = a2((t/2) + (1/4)*sin(2t)) Evaluated from 0 to...

Yeah, helps allot. I have done it that way and failed but I have a knack for making stupid tiny mistakes, like forgetting a minus sign or something. So Il try again. It is nice to know that this stuff is not completely beyond me. :)

I will denote vectors in bold. Homework Statement Show that the curve C given by r=a*Cos(t)Sin(t)i+a*Sin2(t)j+a*Cos(t)k ( 0=<t=<pi/2 ) lies on a sphere centred at the origin. Find \int zdS under C *edit* There is a huge gap here and the equation has dissapered for me. But...

Of course. How stupid of me. I think I have solved it now. I tried again with the new limit and failed, but then I noticed that I by mistake took the square of something that should not be squared. When I correct that mistake it should work out. The source of error in these calculations are...

Ahhhhhh. Now I see... I think. How do I do to form an expression for w then? Or get its limit.

Actually the height is dependent on t. It is a cylinder and R and theta only decides the area of the circle. So that can't be what's wrong. What I'm not 100 percent sure of is the limit.

You are right. I'l check into that. Thanks.

Thanks, you are right. a and b are supposed to be squared in the problem statement. I'll edit it right away.

Homework Statement Solve for the volume above the xy-plane and below the paraboloid z=1-x2/a2-y2/b2 I have gotten an answer that is close to the correct one, but I can't figure out where I am wrong. Homework Equations Solution: Volume is = ab\pi/2 The Attempt at a Solution...