Recent content by pimpalicous

Hey Guys! After suffering something of a quarter life crisis in my senior year in undergrad physics, I decided not to apply for my Ph.d. Instead, I decided I'd like to work professionally as a software engineer. Problem is, I have little formal education in computer science (I took a class in...

so does that mean if we find the inertia tensor at the center of the base of a hemisphere we can use the parallel axis theorem to find the tensor for the center of mass

Is the parallel axis theorem always valid for inertia tensors? We have only seen examples with flat (2d) objects and was wondering if it would also be valid for 3d objects, like a h emisphere, for example. Thanks.

Nope. Think of the formula for KE. Mass is never negative, and even if the velocity is negative, its squared so the negative sign goes away. Gravitational Potential can be negative depending on where you define your potential to be zero. But really, only changes in potential energy are...

What exactly is the "center of force"? For instance, you use reduced mass to make an orbital problem one body. Is the center of force the r "seperation between the bodies"? Or is the center of force at the center of mass? In an ellipse, the center of mass is always at one of the foci, right?

AWESOME Thanks bro!

never mind, I got it.

Homework Statement My professor told me about this problem and I wanted to do it to practice for the test. A rope attached to two fixed points A and B will take the shape that minimizes the potential energy. Find the shape of the curve. Homework Equations mgy df/dy-d/dx(df/dy')=0...

Homework Statement Find all solutions of a for which the resulting linear system has (a) no solution, (b) a unique solution, (c) infinetly many solutions. x+z=4 2x+y+3z=5 -3x-3y+(a^2-5a)=a-8 Homework Equations ...Row reduction The Attempt at a Solution I solved the...

yeah, i was able to get it to that form and it worked. Thanks.

Homework Statement If a ping pong ball is released from rest, how long does it take for the ping pong ball to reach 90% of its terminal velocity? m=2.2g, density(air)=a.29kg/m^3, Cw=.5, diameter=.38mm Homework Equations Fd=1/2*C_{w}+\rho*A*v^2 Newton's second law The Attempt...

Magnus effect! That's what he called it. I thought he said magnus force but I may have misheard him. Thanks!

The other day, my professor mentioned projectiles have a force on them due to their spin. The example he gave is how a baseball curves because of the spin of a curve ball. What's the name of this force?

It's ampere's law applied to a straight wire. (I think you can also derive it from Biot savart) Its used to find the magnetic field due to a straight wire w/current. Picture a bunch of circles, each one centered on the wire. The equation says that the magnetic field is the same at any...