1. 
A reference frame attached to the Earth 




2. 
Two planets of radii R_{1} and R_{2} have the same density. The ratio of their accelerations due to gravity at the surface is 




3. 
An Earth satellite of mass m revolves at a height h from the surface of the Earth. If R is the Earth's radius and g is the acceleration due to gravity at the surface of the Earth, then the velocity of the satellite is given by 




4. 
 The figure shows the elliptical orbit of a planet with the Sun at the focus. The areas of regions 1 and 2 are the same. If the planet takes times t_{1} to go from one end to the other end of region 1 and t_{2} to go from one end to the other end of region 2, then what is the relationship between t_{1} and t_{2}?  




5. 
A satellite orbits at a height h above the Earth's surface. Let R be the Earth's radius. If V_{e} is the escape velocity and V_{o} is the orbital velocity of the satellite orbiting at a height h << R, then 



