- #1

Sean1218

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## Homework Statement

Boat moving at 2.8 m/s [fwd] relative to water (V

_{BW})

Tourists walking on deck at 1.1 m/s relative to deck (V

_{PB})

Determine their velocity relative to the water if they are walking towards the starboard (right side of ship).

## Homework Equations

V

_{PW}= V

_{PB}+ V

_{BW}

## The Attempt at a Solution

V

_{PW}= 1.1 m/s [R] + 2.8 m/s [fwd]

V

_{PB}= 1.1 m/s: x-dir = 0 and y-dir = 1.1 m/s

V

_{BW}= 2.8 m/s: x-dir = 2.8 m/s and y-dir = 0

V

_{PW}= ??: x-dir 2.8 m/s y-dir = 1.1 m/s

So do I just draw a graph? Like, 2.8 in magnitude along the positive x-axis, and then 1.1 in magnitude up (or how would I think about this? like how would I know where to draw the vectors and which direction etc. in a more complicated question?)

and just

c = sqrt(a

^{2}+ b

^{2})

c = 3.01 m/s

V

_{PW}= 3.01 m/s

Then how do I find the direction of V

_{PW}?

[tan

^{-1}(1.1/2.8)] = [E 21.45 N] or [21.45 N of the horizontal] or what? since the question doesn't use direction

Also, how many significant digits should I leave my answers to (both velocity and direction)?

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