Solve Power-Law Spiral With Angular Momentum L

  • Thread starter Thread starter simms_mj
  • Start date Start date
  • Tags Tags
    Spiral
AI Thread Summary
To solve for the potential V(r) that results in a spiral path defined by r = C(theta)^k, the relationship between angular momentum L and the time derivative of theta needs to be clarified. The discussion highlights the need to express r' without involving theta, which is essential for integrating it into the energy equation E = K + V(r). Participants explore whether the prime notation in the angular momentum equation indicates a time derivative of theta, suggesting a connection between r and theta-dot. The challenge lies in eliminating r to derive a usable expression that links r and theta. Ultimately, the focus is on finding a suitable form for V(r) that corresponds to the specified trajectory.
simms_mj
Messages
3
Reaction score
0

Homework Statement



Given L (angular momentum), find the form of V (r) so that the path of a particle is given by the spiral r = C(theta)k, where C and k are constants

Homework Equations



L = mr2(theta)'

The Attempt at a Solution



I know I have to find a expression for r' using no theta's and insert it into the energy formula E = K + V(r) but I am lost on how to apply it.
 
Physics news on Phys.org
Is that prime you have written on theta' in the angular momentum expression the time derivative of theta?

If so, doesn't that give you a relation between r and theta-dot?
The required trajectory is a relation between r and theta. Could you eliminate r between these two and do anything with that?
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top