- #1
karis
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Homework Statement
A. The mass ratio of the Earth and the moon is 81:1 and the earth-moon separation is 3.8x108m. At which position between the Earth and the moon is the gravitational potential at a maximum?
B. Which of the following statement about a communication satellite in parking orbit above the Earth's surface is incorrect?
A. It is accelerating towards the centre of the Earth at all times.
B. It must be in a circular orbit above the Earth's equator
C. It is always vertically above the same place on the Earth's surface
D. It must be rotating in the same sense and with the same angular speed as the earth
E. It is at a height where its gravitational potential energy is numerically equal to its kinetic energy
C. X and Y are two planets. Each of them has a low-altitude satellite revolving in a circular orbit close to the planet. If the two satellites are observed to have the same period, then X and Y must have nearly the same
A. mass
B. average density
C. radius
D. acceleration due to gravity at the planet surface
E gravitational potential at the planet's surface
Homework Equations
The Attempt at a Solution
For A, i have absolutely no idea, I've tried to simply use ratio to get the answer n i failed.
For B, i know A,C and E are correct answers, but why B is correct too?
Thz so much :):):)