Solving Planetary Motion: X & Y's Circular Orbits

AI Thread Summary
Planets X and Y orbit a star with a radius ratio of 5:2. After 5 years, planet X has rotated 92.6 degrees, prompting a calculation of how far planet Y has traveled in the same period. The discussion highlights the application of Kepler's third law to relate the angular velocities of the two planets based on their orbital radii. Users express difficulty in applying the radius ratio to angular velocities correctly. The conversation emphasizes the importance of understanding the relationship between gravitational forces and orbital motion.
lempkema
Messages
7
Reaction score
0

Homework Statement



Planets X & Y travel in circular orbits around the same star. The ratio of the radii of their orbits is 5:2. 5 years after the planets were aligned, planet x has rotated 92.6 degrees. how many degrees has y traveled in the same amount of time?

Homework Equations



v^2=GM/R

Wx=phix/t; Wy=phiy/t

phix= angular of X after t time
phiy= angular of X after t time

The Attempt at a Solution



I just keep getting the wrong answer. I try transferring the ratio of radii to the angular velocities, but i must be doing it wrong.
 
Physics news on Phys.org
Check Kepler's third law.
 
thank you so much, that made to ratio a lot less difficult to apply!
 
Note, that third law can be derived from the F=GMm/r^2.
 
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 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'
Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is(Figure 2): F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
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