Kinematics - Uniform Circular Motion

AI Thread Summary
The discussion focuses on calculating the period, T, of a satellite's orbit using gravitational and centripetal force equations. The user attempts to derive the formula but encounters issues with the angular velocity leading to confusion about the relationship between T and the radius, Rs. It is clarified that T should indeed be proportional to R^(3/2), aligning with Kepler's Third Law. The correct formula for T is confirmed as T = 2πRs/√(GMe). The conversation emphasizes the importance of understanding the relationship between gravitational force and orbital motion.
nahanksh
Messages
38
Reaction score
0

Homework Statement


What is the period, T, of the satellite's orbit (G is the gravitational constant, 6.7 × 10-11 m3 kg-1 s-2) ?
(The picture is attached)http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys211/oldexams/exam1/sp08/fig18.gif


Homework Equations


a = w^2*r
w=2pi/period
F = -Gm1m2/(R^2)

The Attempt at a Solution



Using the force equation and "a=F/m",

I got a = GMe/Rs^2

And using a = w^2*Rs,

GMe/Rs^2 = w^2*Rs

Then, the angular velocity keeps having Rs^3 which doesn't seem to be right when compared to the answer...

What's wrong with my attempt?
Please help me out here...


The answer should be "T= 2*pi*Rs/sqrt(GMe)
 
Last edited by a moderator:
Physics news on Phys.org
nahanksh said:
The answer should be "T= 2*pi*Rs/sqrt(GMe)


No, T should definitely be proportional to R3/2, that's where Kepler's Third Law comes from.
 
Oh, so you think what i was doing was right..?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top