Question

A kite is flying at a height of 3 metres and 5 metres of string is out. If the kite is moving away horizontally at the rate of 200 cm/s, find the rate at which the string is being released.

Answer 1

(5)² = x² + (3)²

25 = x² + 9

16 = x²

x² = 4²

x = 4

`dx/dt` = 200 cm/s

x² + 3² = y²

`2x dx/dt = 2ydy/dt`

`4(200) = 5dy/dt`

`(4 xx 200)/5= dy/dt`

`dy/dt` = 160 cm/s