Recent content by FruitNinja

1. Planet orbiting around a star whose mass changes

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
2. Planet orbiting around a star whose mass changes

1. Homework Statement (Assuming all circular orbits) 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 be...
3. ORBIT: change in orbital distance

Thank you for the help gneill! I'll try that when I get the chance.
4. ORBIT: change in orbital distance

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
5. ORBIT: change in orbital distance

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 not r 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
6. ORBIT: change in orbital distance

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?
7. ORBIT: change in orbital distance

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
8. ORBIT: change in orbital distance

1. Homework Statement we know the mass of the moon, Mm, and the earths, 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...
9. Potential Energy function for this system

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
10. Potential Energy function for this system

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
11. Potential Energy function for this system

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
12. Potential Energy function for this system

Supported? By the 2 tension forces of the 2 outer blocks upward. But that would be internal
13. Potential Energy function for this system

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...
14. Potential Energy function for this system

1. 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...
15. Time it takes for block to slide down an incline in elevator

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