Register to reply

Kepler's Laws problems

by Steven-
Tags: kepler, laws
Share this thread:
Nov7-05, 06:35 PM
P: 5
1) Satellite X and Satellite Y orbit the earth. The distance between X and the earth is 8 times greater than the distance between Y and the earth. Using Kepler's Laws, the period of satellite X is what factor times the period of satellite Y?

R is the distance between satellite Y and the earth

I used Kepler's third law:

T^2=R^3 for Y
T^2=(8R)^3 for X

So T for Y would be R^(3/2)
and T for X would be 22.6*R^(3/2)

So the factor is 22.6 right? But the answer key says "4.0" So am I right?

2) There is a point between the earth and the moon where the net force of gravity on an object located at that point would be zero. I have no idea which formula to use on this problem, please help.
Phys.Org News Partner Science news on
'Smart material' chin strap harvests energy from chewing
King Richard III died painfully on battlefield
Capturing ancient Maya sites from both a rat's and a 'bat's eye view'

Register to reply

Related Discussions
Kepler's Laws Introductory Physics Homework 5
Kepler's Laws Problem Introductory Physics Homework 2
Kepler's Laws Introductory Physics Homework 4
Kepler's Laws Astronomy & Astrophysics 21
Kepler's Laws Astronomy & Astrophysics 28