Recent content by FruitNinja

yes, I know it is really not circular but It will be assumed in this probem. I used f=ma to come up with vi=sqrt(GM/ri) & vf=sqrt(GM/2rf)and plugged in those as V on both sides (with the corresponding r) I got 2 ri = rf

Homework Statement (Assuming all circular orbits) [/B] Say there is a star with mass M and a planet orbiting that star with a mass m. The star M then suddenly loses half of its mass. (So now it is M/2) What is the new radius of orbit of the planet around the star? Warning: Velocity will not...

Thank you for the help gneill! I'll try that when I get the chance.

Yes, doing f=ma I got v^2 =GM/r. Now I have v in terms of r, G, & m. This must be it. So now I would be able to use conservation of angular momentum

Ok, I came up with this: but I don't know the initial/final velocities of the moon. I could use 2 pi r / T if I was given T but I am notr x p = rp (since right angle) Iω + r x p = Iω + r x p IEarth ωearth initial + dinitial vinitial mmoon = IEarth ωearth final + dinitial vfinal mmoon

Because the Earth would not be a perfect sphere anymore right? So would I use momentum conservation in this one with the moon being r x p?

Oh I understand how the Earth slows down now. But why does this affect the moon's orbit? Because the force of gravity doesn't change because the Earth does not become more massive or something

Homework Statement we know the mass of the moon, Mm, and the Earth's, Me, and also the initial distance between their centers as the moon orbits the earth, Rem. Now if the earth’s angular velocity about its own axis is slowing down from a initial given angular velocity, ωi to a final angular...

So is it asking for the change of PE from the y position to the equilibrium? Because there needs to be some kind of change

But I don not understand how that would help with finding the change in potential energy of the system since this isn't an f=ma problem

I mean the tension force is upward (direction) Edit: I mean for the outer blocks it is upward. for the middle one it is at an angle

Supported? By the 2 tension forces of the 2 outer blocks upward. But that would be internal

Hmm so I guess if we think of them as 3 separate PEs then 2 of them are decreasing when the 3rd is increasing. so that would change pe. i see that now. But still, the whole system looks static, like it is not moving or changing. Is there some kind of force that would push the middle one down...

Homework Statement Find the potential energy function for the three mass, earth, and pulley system as shown. The potential energy will be as a function of the vertical position downward as shown in the diagram. Also, find the equilibrium position of this system. The two outside masses are...

Yes, if we were not in a elevator yes. But that would be a non-inertial frame so we can't do that, according to my teacher