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Two boats, Mary Jo and Suzie, leave port at the same time. Mary Jo sails at 10 knots on a bearing of065°. Suzie sails on a bearing of 120° and after 1 hour Mary Jo is on a bearing of 330° from Suzie.What is Suzie’s speed? (A knot is a nautical mile per hour

I have drawn tge diagram but i have no clue what to do. Plz help
Original post by yeah1106
Two boats, Mary Jo and Suzie, leave port at the same time. Mary Jo sails at 10 knots on a bearing of065°. Suzie sails on a bearing of 120° and after 1 hour Mary Jo is on a bearing of 330° from Suzie.What is Suzie’s speed? (A knot is a nautical mile per hour

I have drawn tge diagram but i have no clue what to do. Plz help


Having drawn the diagram, you should have all the angles.

Now the distance travelled is proportional to the speed, so rather than think of the sides as representing positions/displacements, you can also think of them as representing the velocities. Sine rule should now take care of it.
(edited 8 years ago)
Original post by ghostwalker
Having drawn the diagram, you should have all the angles.

Now the distance travelled is proportional to the speed, so rather than think of the sides as representing positions/displacements, you can also think of them as representing the velocities. Sine rule should now take care of it.


Yep, that idea works as I have just tested it.

Work out the angles, then draw the diagram
You should know what the sine rule is - use that, plug in your values and rearrange for the speed that you are calculating.
Reply 3
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yeah1106
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Original post by spotify95
Yep, that idea works as I have just tested it.

Work out the angles, then draw the diagram
You should know what the sine rule is - use that, plug in your values and rearrange for the speed that you are calculating.


i have tried but i am getting the wrong answer
Original post by yeah1106
i have tried but i am getting the wrong answer


Hi,

Do you know what the correct answer should be?

Is it possible for you to attach your workings out so far, so I can have a look and see where, if anywhere, you're going wrong?

I managed to work out an answer last night but I don't know whether it is correct or not. (And in any case, just providing an answer out of nowhere isn't going to help.)

Thanks.
Reply 5
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yeah1106
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Original post by spotify95
Hi,

Do you know what the correct answer should be?

Is it possible for you to attach your workings out so far, so I can have a look and see where, if anywhere, you're going wrong?

I managed to work out an answer last night but I don't know whether it is correct or not. (And in any case, just providing an answer out of nowhere isn't going to help.)

Thanks.


the answer is 19.9 knots did u get that??
Original post by yeah1106
the answer is 19.9 knots did u get that??


Nope, I got something totally different. I will have to try again tonight to see if I can get a working out for you.

Have you managed to get the correct answer yet?
Reply 7
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yeah1106
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Original post by spotify95
Nope, I got something totally different. I will have to try again tonight to see if I can get a working out for you.

Have you managed to get the correct answer yet?


no
Perhaps you could upload your diagram - to make sure we're on the correct path here ?
Reply 9
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yeah1106
OP
10
Original post by spotify95
Nope, I got something totally different. I will have to try again tonight to see if I can get a working out for you.

Have you managed to get the correct answer yet?


i figured it out thx for your help
Original post by yeah1106
i figured it out thx for your help


No worries, glad to be of help! :smile:

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