1. 
The ratio of the time periods for two satellites of equal mass in circular orbits of radii R and 9 R is 




2. 
 Consider a hole drilled into the Earth and an object placed at the bottom of the hole (point P) as shown in the figure. The gravitational force of attraction on the object will be due to  




3. 
 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}?  




4. 
If a simple pendulum with a time period of 2 seconds is made to oscillate at a height R equal to the Earth's radius, then its time period at this height will be 




5. 
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 



