I hope it is clearly visible.. Velocity of the center of mass of 2-ball system is - 11.54m/s. Minus indicates, velocity direction is in downward direction.
Time period of any moon of Jupiter is given by

from above formula we can say that mass of Jupiter is given by

now for part a)

T = 1.77 day = 152928 seconds
now by above formula



Part B)

T = 3.55 day = 306720 seconds
now by above formula



Part c)

T = 7.16 day = 618624 seconds
now by above formula



PART D)

T = 16.7 day = 1442880 seconds
now by above formula



Convection is the movement<span> of groups of molecules within </span>fluids<span> such as gases and liquids, including molten rock (rheid).</span>
Answer:
The ball will have a kinetic energy of 0.615 Joules.
Explanation:
Use the kinetic energy formula

The kinetic energy at the moment of leaving the hand will be 0.615 Joules. (From there on, as it ball is traveling upwards, this energy will be gradually traded off with potential energy until the ball's velocity becomes zero at the apex of the flight)