Help Check My Homework: Two Boats & Passenger Speed

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Homework Help Overview

The problem involves two boats moving away from shore, with one boat moving north and the other at an angle relative to the first. A passenger on the second boat is also moving across the deck. The objective is to determine the passenger's speed relative to the shore.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to set up vectors for the boats and the passenger, calculating their components to find the resultant speed. Some participants question the definitions of the axes used in the vector setup, particularly regarding the orientation of north and east.

Discussion Status

The discussion is ongoing, with participants clarifying the setup of the problem and addressing potential misunderstandings regarding the direction of the vectors. There is no explicit consensus yet, but the dialogue is focused on ensuring the correct interpretation of the problem.

Contextual Notes

Participants are discussing the relative velocities of the boats and the passenger, with some confusion about the coordinate system being used. The original poster's calculations are based on their interpretation of the problem statement.

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I tried looking at the other threads on this but they seem incomplete.
I would like someone to check my work.

Homework Statement


Two boats are heading away from shore. Boat 1 heads due north at a speed of 3 m/s relative to the shore. Relative to Boat 1, Boat 2 is moving 40° north of east at a speed of 1.7 m/s. A passenger on Boat 2 walks due east across the deck at a speed of 1.1 m/s relative to Boat 2. What is the speed of the passenger to the shore?


Homework Equations


x and y vectors.


The Attempt at a Solution


I set up vectors for each moving object.

B1x = 0 B2y = 0

B2x = 1.7cos(40°) B2y = 1.7sin(40°)

Px = 1.1 Py = 0

I added the x and y components

Rx = 0 + 1.302 + 1.1 Ry = 0 + 1.09 + 0

= 2.402 = 1.09

Sp^2 = (2.402)^2 + (1.09)^2
Sp ≈ 4.74 m/s.
 
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If those vectors are the velocities relative to the shore, then surely B1x=0 and B1y=3 m/s ? ( y being East).
 
Mentz114 said:
If those vectors are the velocities relative to the shore, then surely B1x=0 and B1y=3 m/s ? ( y being East).

Don't you mean y being N?
 
haruspex said:
Don't you mean y being N?
On re-reading the question, yes, I mean North.
 

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