The speed of landing is 15.69 ft/sec.
<h3>What is differentiation ?</h3>"Differentiation, in mathematics, process of finding the derivative, or rate of change, of a function. In contrast to the abstract nature of the theory behind it, the practical technique of differentiation can be carried out by purely algebraic manipulations, using three basic derivatives, four rules of operation, and a knowledge of how to manipulate functions.
The three basic derivatives (D) are: (1) for algebraic functions, D(xn) = nxn − 1, in which n is any real number; (2) for trigonometric functions, D(sin x) = cos x and D(cos x) = −sin x; and (3) for exponential functions, D(ex) = ex."
Let the length of the rope = r
Height of the balloon = h
we are given dr/dt = 15ft/sec
at any time t we know:
By the Pythagoras theorem we know:
We have to find dh/dt at time t = 20 sec
By chain rule:
--------------------- at time t = 2
=15.69 ft/sec
Hence dh/dt = 15.69 ft/sec
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