Recent content by jwu

So basically you mean the work-energy theorem and the conservation of energy equation are interchangable at some point?

Homework Statement All we know the gravitational potential energy is U=-GMm/r. But when I got confused when I was trying to understand the proof of this equation. Homework Equations Here's what they did: W by grativity=GMm(1/r2-1/r1) Therefore, since △Ugrav=-W by grav, we get...

Homework Statement A satellite of mass M is in a circular orbit of radius R around the earth. (a) what is its total mechanical energy (where Ugrav is considered zero as R approaches infinity)? (b) How much work wouldbe required to move the satellite into a new orbit, with radius 2R...

Homework Statement A cylinder of mass M and radius R rolls(without slipping) down an inclined plane whose incline angle with the horizontal is Θ. Determine the acceleration of the cylinder's venter of mass.(Derive the formula) Homework Equations I have the answer, but I just don't...

You are amazing! This really helps a lot! Just enlightening! How can I add you as a forum friend?

So you mean the Mechanical energy is conserved because the frictional force that causes the rolling dose no work?

But the prolem is that it's the answer on the Priceton AP physics book. It stated that "we will attack this problem using Conservation of Energy." Then it comes out something like: Ki+Ui=Kf+Uf 0+Mgh=(1/2Mv^2+1/2Iw^2)+0 any ideas? Thank you anyway!

I just have a kind of conceptual question. I am doing a problem. It's related to a ball rolling from a inclined plane without slipping. The answer uses the Conservation of Mechanical Energy to attack that problem. But isn't true that Conservation of Mechanical Energy can only be used when there...