Answer:
The wind would still blow, but it would curve and spin in the opposite direction.
Explanation:
What you know:
Vi=0m/s
Vf=143.8m/s
A=-9.8m/s
d=???
Use the equation Vf^2=Vi^2+2A(d)
Rearrange to isolate d: d=Vf^2/2A
d=(143.8)^2/2(-9.8)
d=20678.4/-19.6
d=-1055m
The tank was released from a height of 1055m
Explanation:
The given data is as follows.
Velocity of bullet,
= 814.8 m/s
Observer distance from marksman, d = 24.7 m
Let us assume that time necessary for report of rifle to reach the observer is t and will be calculated as follows.
t =
(velocity in air = 343 m/s)
= 0.072 sec
Now, before the observer hears the report the distance traveled by the bullet is as follows.

= 
= 58.66
= 59 (approx)
Thus, we can conclude that each bullet will travel a distance of 59 m.
Yes, yes, we know all of that. It certainly took you long enough to
get around to asking your question.
If
a = (14, 10.5, 0)
and
b = (4.62, 9.45, 0) ,
then, to begin with, neither vector has a z-component, and they
both lie in the x-y plane.
Their dot-product a · b = (14 x 4.62) + (10.5 x 9.45) =
(64.68) + (99.225) = 163.905 (scalar)
I feel I earned your generous 5 points just reading your treatise and
finding your question (in the last line). I shall cherish every one of them.