HSC 2003 Q7a Help (1 Viewer)

[bujolover]

Hi guys,

Q: David is in a life raft and Anna is in a cabin cruiser searching for him. They are in contact by mobile telephone. David tells Anna that he can see Mt Hope. From David’s position the mountain has a bearing of 109°, and the angle of elevation to the top of the mountain is 16°.
Anna can also see Mt Hope. From her position it has a bearing of 139°, and the top of the mountain has an angle of elevation of 23°.
The top of Mt Hope is 1500 m above sea level.
Find the distance and bearing of the life raft from Anna’s position.


See the diagram in this link, cos I can't attach it to this post (I copied the question here just in case the link doesn't work for any of you):
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2003exams/pdf_doc/mathemat_ext1_03.pdf

The bearing in the answer doesn't make sense. The direction of north from the mountain seems to be different from the north from Anna (at least, if you gauge from what the answer says), which doesn't make sense to me. Cos, the bearing of David is given to be 109° from the mountain (so if you draw the north arrow from the mountain on the page, it's pointing towards the bottom of the page), whereas the bearing of David from Anna is 250° (nearest deg.), according to the given answer, meaning that the north arrow from Anna points towards the top of the page. But, from what I've been taught, I would take north from Anna to be parallel to and pointing in the same direction as the north from the mountain. The bearing I initially got, for those of you who want to know, is 028°T, which makes more sense to me from what I understand.

BTW, I get the distance- 2799m; don't worry about that part.

I hope what I have asked makes sense (and sorry if I sounded extremely repetitive). If it does, please clarify why there are two "norths" in the same situation... -_-

 

[integral95]

Hi guys,

Q: David is in a life raft and Anna is in a cabin cruiser searching for him. They are in contact by mobile telephone. David tells Anna that he can see Mt Hope. From David’s position the mountain has a bearing of 109°, and the angle of elevation to the top of the mountain is 16°.
Anna can also see Mt Hope. From her position it has a bearing of 139°, and the top of the mountain has an angle of elevation of 23°.
The top of Mt Hope is 1500 m above sea level.
Find the distance and bearing of the life raft from Anna’s position.


See the diagram in this link, cos I can't attach it to this post (I copied the question here just in case the link doesn't work for any of you):
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2003exams/pdf_doc/mathemat_ext1_03.pdf

The bearing in the answer doesn't make sense. The direction of north from the mountain seems to be different from the north from Anna (at least, if you gauge from what the answer says), which doesn't make sense to me. Cos, the bearing of David is given to be 109° from the mountain (so if you draw the north arrow from the mountain on the page, it's pointing towards the bottom of the page), whereas the bearing of David from Anna is 250° (nearest deg.), according to the given answer, meaning that the north arrow from Anna points towards the top of the page. But, from what I've been taught, I would take north from Anna to be parallel to and pointing in the same direction as the north from the mountain. The bearing I initially got, for those of you who want to know, is 028°T, which makes more sense to me from what I understand.


BTW, I get the distance- 2799m; don't worry about that part.

I hope what I have asked makes sense (and sorry if I sounded extremely repetitive). If it does, please clarify why there are two "norths" in the same situation... -_-

Nope it's the bearing from David's perspective, not the mountain's.

 

[bujolover]

Nope it's the bearing from David's perspective, not the mountain's.

Oh my god, I can't believe this...I didn't even comprehend that it said the bearing from David to the mountain was 109°. I actually don't understand how I did not notice that it said the bearing from David, and kept thinking it was from the mountain, after attempting that question at least three times, and on different days, too. >.< How didn't I even notice this as I was typing the question up here??? *face palm*
Anyway, thank you so much for finally making me realise that I misunderstood an important part of the question and made this simple question a difficult one for myself.