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Ebudo
Nov 16, 2009, 04:14 PM
Please can you explain to me how to answer his question:
At 2pm, two ships A and B start imultaneously from points that have position vectors 4i+11j and 10i+j respectively relative toa port. ShipA maintains a steady velocity of 3i+j. if the velocity os shipA relative to shipB is 4i-j, find
I,the velocity of ship B
ii,the time at which the ships are nearest to each other
iii,the least distance between the ships
I've,the position vector of the ships relative to the port at the time they are nearest to each other...
I really need the steps and explanations to this problem...

Unknown008
Nov 16, 2009, 08:51 PM
1. You need a sketch to make it easier.

On graph paper, you can find the velocity of the ship A;

26595

2 & 3. You know relative velocity and you can find the relative distance apart. Use both to get the time. It's similar to a situation where one of the ships remains still (using relative velocity) and the other one passes by it. In other words, it's like finding the perpendicular distance from a point to a line.

4. From then, you can find their positions, which turns out to be the vector position from the port (with coordinates (0, 0)

Give it a try and post your work, and answer.

Ebudo
Nov 19, 2009, 02:49 PM
Alrte, thankss... willl try it and post it for you to verify.. thanks a lot...

Unknown008
Nov 19, 2009, 07:22 PM
You're welcome! :)

Chris-infj
Nov 20, 2009, 10:54 AM
Hi Edudo,

Here's my take on the problem.

Ebudo
Dec 25, 2009, 04:33 PM
Thankss chris, am just seeing your post... thanks a lot...