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Bearings maths question

Martin and Janet are in an orienting race
Martin runs from checkpoint A to checkpoint B , on a bearing of 065
Janet is going to run from checkpoint B to checkpoint A
Work out the bearing of A from B

Reply 1

Good bloke

Original post by M.V

Martin and Janet are in an orienting race
Martin runs from checkpoint A to checkpoint B , on a bearing of 065
Janet is going to run from checkpoint B to checkpoint A
Work out the bearing of A from B

A backbearing is always found by adding or subtracting 180 to the original bearing, so the backbearing for 065 is 245 (and vice versa).

The backbearing for due north (000) is due south (180).

Reply 2

M.V

The bearing of a ship from a lighthouse is 050work out the bearing of the lighthouse from the ship

Reply 3

Notnek

Original post by M.V

The bearing of a ship from a lighthouse is 050work out the bearing of the lighthouse from the ship

Have you drawn a diagram? Can you please show us? Good Bloke has given you a quick way of working out the back bearing but I recommend understanding why this works.

Original post by Good bloke

This is trivial and should be obvious..

Surely that depends on the study level / ability of the student?

Reply 4

Good bloke

Original post by Notnek

Surely that depends on the study level / ability of the student?

It does. I'd expect a pupil to emerge from primary school in full possession of the requisite knowledge though. Knowing N is 000 and S is 180 is enough.

Reply 5

username1732133

Original post by Good bloke

It does. I'd expect a pupil to emerge from primary school in full possession of the requisite knowledge though. Knowing N is 000 and S is 180 is enough.

"Eight take away one? Is it still 8?" That's a quote from one of my year eleven students from a few years ago. I'm not posting this to ridicule my student but rather to point out that what is obvious to you is not obvious to everyone and what you expect to be the case is not always the case.

Reply 6

Purdy7

It has nothing to do with the students ability or intelligence, it does however, show which ones have a good memory recall and that is it, in fact that is all any exam does.

Doing the bearings in your head is fine, but you need to show the examiner the way you got to it, so draw in the north line, and the journey, then use the protractor to get the degrees, you'll score extra points just for a few lines.

Reply 7

Notnek

Original post by Purdy7

It has nothing to do with the students ability or intelligence, it does however, show which ones have a good memory recall and that is it, in fact that is all any exam does.

You need more than a good memory to well in a maths exam paper. Memory won't really help you much.

Doing the bearings in your head is fine, but you need to show the examiner the way you got to it, so draw in the north line, and the journey, then use the protractor to get the degrees, you'll score extra points just for a few lines.

You don't need to use a protractor to do this question and using a protractor could lead to mistakes.

Reply 8

Purdy7

I agree, but they would get extra markings for showing how they got to the result rather then just shoving the number on the answer line. Also if you work out the degrees then double check one way or the other you'll have confirmed the answer is correct.