Recent content by phenalor

nvm, found the solution

Homework Statement A mass-spring-dampener system is applied a force mg and is immediatly removed, setting the system in motion. The system is constantly applied force Mg and is static at y=y_0. Find a formula for both A and \phi Homework Equations \ddot{y}+2\delta\dot{y}+w_0^2y=0...

Sorry I have been gone for so long, lots of examns coming up soon. Thank you everyone for explaining this to me. It seems i had forgotten the relationship between \Delta x and dx, which is really embarrrasing. The reason I got stuck upon this is that i thought I = \int{r^2}{dm} \rightarrow...

The problem is I don't know how to solve it. I agree that it must have been looked upon, but i have a hard time just accepting things like this. I want to know how and why and see a proof. It's a curse really (:

your dV = 2 * pi * r * dr is equivalent with my 2Δr*r + Δr^2 what i dislike is the 'removal' of dr^2. It shrinks faster, but they both approach 0. on the other hand, is it even possible to solve \int(dr + dr^2)

Homework Statement When calculating moment of inertia of a disk there is something that really bothers me. I've googled this a lot and everywhere i look they 'assume' that the Δa = Δr*2∏r, formula for rectangle, not circle: (area of circle r+Δr - area of circle r) Δa = ∏(r+Δr)^2 - ∏r^2 = ∏r^2 +...