J
James Harwood
Guest
A boat sails at a speed of 11 knots due east. The current flows on a bearing of 210° at a speed of 5 knots. Find the resultant speed of the boat.
With the diagram one would use the cosine rule to work this out, so that's quite simple . . the solution is 7.123 knots.
http://i166.photobucket.com/albums/u94/j...
That's my diagram, but for some reason the book uses cos30 instead of cos60 like I would have. WHY?!?!?!?!
Please provide working - and an explanation (preferably with a description of a diagram or drawing one) that can explain to me why you use cos30 instead of cos60.
BEST ANSWER GETS 5 STARS, the solution is 7.123 knots.
OOOPS SORRY = HERES THE LINK
http://i166.photobucket.com/albums/u94/joshmohoboob/mechanics.jpg
With the diagram one would use the cosine rule to work this out, so that's quite simple . . the solution is 7.123 knots.
http://i166.photobucket.com/albums/u94/j...
That's my diagram, but for some reason the book uses cos30 instead of cos60 like I would have. WHY?!?!?!?!
Please provide working - and an explanation (preferably with a description of a diagram or drawing one) that can explain to me why you use cos30 instead of cos60.
BEST ANSWER GETS 5 STARS, the solution is 7.123 knots.
OOOPS SORRY = HERES THE LINK
http://i166.photobucket.com/albums/u94/joshmohoboob/mechanics.jpg