Answer:

Explanation:
Given that the airplane starts from the rest (this is initial velocity equals to zero) and accelerates at a constant rate, position can be described like this:
where x is the position, t is the time a is the acceleration and
is initial velocity. In this way acceleration can be found.
.
Now we are able to found velocity at any time with the formula: 
Choice C.
That's when convection stops.
The answer for that questions will be 759. Stars itir