Question

One end of a rope is fastened to a boat and the other end is wound around a windlass located on a dock at a point 4m above the level of the boat. If the boat is drifting away from the dock at the rate of 2m/min, how fast is the rope unwinding at the instant when the length of the rope is 5m? ...?

Answer 1

it seems that you need to solve this using phytagoras

x^2 + 4^2 = D^2

2xx' = yy'

y' = xx'/y

y' = 3x2/5

= 6/5

hope this helps