<span>So the question is what gases form the atmosphere of Uranus. So Uranus and Neptune are classified as "ice giants". They have a similar atmosphere to "gas giants" Saturn and jupiter and Neptunes atmosphere is primarily composed out of hidrogen and helyum. So the correct answer is a.</span>
The stone's altitude at time
is given by

where
is the acceleration due to gravity. The stone reaches the ground when
:

The answer would be C. (:
Kepler's three laws of planetary motion can be stated as follows: (1) All planets move about the Sun in elliptical orbits, having the Sun as one of the foci. (2) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.