Question

A ship is to reach a place $10°$ south of the west. In what direction should it be steered if declination at the place is $17°$ west?

• A. East of Magnetic North at angle $83°$
• B. East of Magnetic South at angle $83°$
• C. West of Magnetic North at angle $83°$
• D. West of Magnetic South at angle $83°$

Answer 1

The correct option is C

West of Magnetic North at angle $83°$

Step 1. Given data:

Ship's destination = $10°$ south of the west.

declination at the place = $17°$ west

Step 2. Formula used:

We will use $\theta =90°-\alpha$

Where $\theta ,\alpha$ are the angles.

e.g $GN$=General north, e.g. $MN$= Magnetic north, and so on.

Step 3. Calculations:

1. As the ship has to reach a place $10°$ south of the west.
2. And declination at the place is $17°$ west.
3. So the initial position is at $17°MN$ from $GN$.
4. So the angle between $MN$ and $GW$=$90°-17°=73°$
5. Now, the ship has to reach at point A, Which is at $10°$from $GW$.
6. Thus the ship must be steered to an angle $73°+10°=83°$West of Magnetic North.

Hence, the correct option is option C.