I'm assuming the question is time it will take for ball to reach ground, if it is then set equation to zero then use the quadratic formula, the possible t value is your answer then
You don't need to worry about the 10 year bit with this question. Just grab a calculator and divide 100/2, then the answer to that (50) by 2 etc and keep dividing by 2 until you get down to 6.25.
The answer ends up being 4 half lives :)
If you don't understand what a half life is please let me know :)
Answer:
(a) Ratio of mean density is 0.735
(b) Value of g on mars 0.920 
(c) Escape velocity on earth is 
Explanation:
We have given radius of mars
and radius of earth 
Mass of earth 
So mass of mars 
Volume of mars 
So density of mars 
Volume of earth 
So density of earth 
(A) So the ratio of mean density 
(B) Value of g on mars
g is given by 
(c) Escape velocity is given by

Answer:
4.4 square meters = 47 square foot
Explanation:
We have
1 meter = 3.28084 foot
1 square meter = 3.28084 x 3.28084 square foot = 10.76 square foot
4.4 square meters = 4.4 x 10.76 = 47.36 square foot = 47 square foot
4.4 square meters = 47 square foot
There is no SI "base unit" of density.
(Any unit of mass) divided by (any unit of volume) is
a valid unit of density.
The units of density that are seen most often are
(gram per cm³) and (kgm per meter³) .