A ship sails 12km on a bearing of 250, then changes course to a bearing of 135, and sails a further 18km. Find the bearing it would need to sail on, and the distance it would need to travel, inorder to get back to its starting point.
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A ship sails 12km on a bearing of 250, then changes course to a bearing of 135, and sails a further 18km. Find the bearing it would need to sail on, and the distance it would need to travel, inorder to get back to its starting point.
Draw a clear diagram
Horizontally
Moves left 12 sin 70
Moves right 18 cos 45
To move back to start move left 18 cos 45 - 12 sin 70
Vertically
moves down 12 cos 70
moves down 18 sin 45
To move back to start move up 12 cos 70 + 18 sin 45
To get distance use Pythagoras on right angled triangle with hypotenuse unknown and other sides 12 cos 70 + 18 sin 45 and 18 cos 45 - 12 sin 70
To get bearing do the inverse of tan on (18 cos 45 - 12 sin 70)/(12 cos 70 + 18 sin 45)
Then subtract this angle from 360
Remember bearings are written as three figures
ok it was extremely confusing at first since i have no idea where the right angle came in, but i suppose you drew a straight line from the 45 angle to the right, and then down to the point after the 18km was travelled. But anyway after that i managed to work it out.
Sorry. Didn't have time to draw a diagram