If they both start from the same height, then they both hit the ground at the
same time. It makes no difference if their horizontal speeds aren't equal.
The cannon ball still accelerates downward at the same rate as the baseball.
Answer:
The ratio of the orbital time periods of A and B is 
Solution:
As per the question:
The orbit of the two satellites is circular
Also,
Orbital speed of A is 2 times the orbital speed of B
(1)
Now, we know that the orbital speed of a satellite for circular orbits is given by:

where
R = Radius of the orbit
Now,
For satellite A:

Using eqn (1):
(2)
For satellite B:
(3)
Now, comparing eqn (2) and eqn (3):

Answer:
since -6 lasted for 5 seconds, multiplying both would result in -30
3 lasted for 10 seconds, so multiplying both would give +30
average = ( 30 + (-30) ) / 2
30 -30 is already equal to zero, so the answer should be 0
D is the correct answer!!