[mxmadman44]

This is a problem i was set for the summer. I have to do it in excel so i know i have to come up with a equation. I understand the theory its just making an equation and understainding how to place this in excel.

The Problem: There is a ship's navigator needs to know the true direction and speed of travel of a ship when sailing in a current.

The task is to produce 2 clearly formated tables of theta, the actual direction of travel and S the actual speed of the vessel. The two variables are:

* D , the angle between the direction in which the ship is pointing and that of the current.
* R , the percentage ratio of the current speed to ship speed. E.g. if the current speed is half the ship speed, then R = 50%

Then i have to illustrate how the true bearing thetaand speed S of the ship will change with D and R as follows:

Make 2 tables, one for theta and one for S, for values of deltaD between -180 or +180 (pi and -pi) , and for R between 0% and 200%

the graphs i am going to include are theta against D for different values of R
and
S vs R for different D

i have been given hint's which i didnt find useful but you might.
1: Assume the ship has a speed of 1 unit and i spointing directly ahead.
2: think how to simplify results

i know that R and D can effect theta and S but its has been bugging me how do i place this in excel and where to start with an equation. I have placed it all into excel but get a negative reading for the direction which is wrong as obviously it should be between 0 and 360.

Any help at all on this would be much appreciated as i have spent the last 2 week's on this and time is running out!

thankyou in advance

[-Em-]

You might get more help in the Maths forum. It's a vector problem, not a general Excel issue