Here’s an interesting (and practical) problem
given to me by my brother-in-law Steve Curtis, captain of the Capullo
sportfishing boat out of Playa Tamarindo, Costa Rica:
Suppose your boat is anchored near the shore of a channel in which there is a steady current, and you are planning to run to a dock directly across the channel on the opposite shore. There are two ways one might steer the boat to the dock:
· the crabbing method: steer a steady course with the nose of the boat pointed somewhat upstream, so the boat maintains a fixed orientation and crabs in a straight line across the channel
· the pointing method: keep the nose of the boat pointed directly at the dock
Which method gets the boat to the dock faster, and by how much? (Assume the boat runs at a constant speed relative to the water, which is faster than the speed of the current relative to the shore.)
Answer :