Calc fun: A boy is flying a kite. He is holding the string at a point 4 feet above the ground.
The kite is 90 feet high and is moving horizontally downwind.

If the boy is paying out string at a rate of 4.5 feet per second,
how fast is the kite moving downwind when 190 feet of string are out?
Assume the kite string is taut.

Question

Calc fun: A boy is flying a kite. He is holding the string at a point 4 feet above the ground. 
The kite is 90 feet high and is moving horizontally downwind. 

If the boy is paying out string at a rate of 4.5 feet per second, 
how fast is the kite moving downwind when 190 feet of string are out? 
Assume the kite string is taut.

anonymous · Answer

Ah, related rates... did you draw a picture?

anonymous · Answer

Tried to but no confidence in my picture being completely correct as I can't get the right answer :-(

anonymous · Answer

|dw:1412694247655:dw|
we want dx/dt.

how are x and h related?