# Homework Help: Relative Motion

1. Jun 12, 2007

### Momentum09

Hello,

Could somebody please give me clues as to how to do this problem?

A ship cruises forward at vs = 4 relative to the water. On deck, a man walks diagonally toward the bow such that his path forms an angle delta = 28 degrees with a line perpendicular to the boat's direction of motion. He walks at vm = 2 m/s relative to the boat. At what speed does he walk relative to the water?

Thank you!

2. Jun 12, 2007

### nrqed

$\vec{v}_{mw} = \vec{v}_{ms} + \vec{v}_{sw}$
where my notation is ms = man with respect to the ship, mw = man with respect to the water, etc.

Just add the two vectors and find the magnitude of v_(mw)