Lighthouses Ports
Friday, August 19th, 2011lighthouses ports
Maths Revision?
A Buoy is 80 km from Port A on bearing 060degrees
A Lighthouse is 100km from the buoy on bearing of 135 degrees
A ship sails from the Port to the Lighthouse
Calculate the shortest distance between the buoy and the ship along it's journey.
Sorry, it comes with a diagram but i can't draw it.
Thanks Peateargryfin, so to complete the question i draw a line from the buoy to the ship line (143.3km long) and use the sine rule?
To get 79.34??
I have drawn a diagram.
http://i31.tinypic.com/2rruyhu.jpg
I have also drawn in a line at a bearing of 270 degrees that passes through the buoy, this gives a right angled triangle.
Using that we can work out the angle x at the buoy.
(the bearing is 60 degrees, one is a right angle and so the other must be 30 degrees)
The diagram shows clearly that the line I have added in as at right angles to the north line of the buoy.
So now there is enough information to say: In a circle there are 360 degrees and we are going to take off the angles we know to find the angle x.
This angle x is 360 - 90 - 30 - 135 = 105 degrees.
We now have two lengths and one angle so we can use the cosine rule.
c² = a² + b² - 2abcosC
c² = 80² + 100² - 2*80*100*cos(105)
c² = 6400 + 10000 -16000*(-0.258819)
c² = 20541.1047216
c = 143.3 km
c is the distance from the buoy to the ship
 |
The hand book of the lower Delaware River; ports, tides, pilots, quarantine stations, light-house service, life-saving and maritime reporting stations List Price: $21.75 Sale Price: $14.38  |
|
This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process... |
 |
The Adventures Of Port Herman Lighthouse List Price: $14.95 Sale Price: $13.45 |
|
The Adventures of Port Herman Lighthouse was inspired from actual events at Point Hueneme Lighthouse. Many visitors were at first dismayed by the lighthouse?s unusual architectural style and surroundings... |
 |
Geographical encyclopaedia of New South Wales : including the counties, towns, and villages within the colony, with the sources and courses of the rivers and their tributaries : ports, harbours, light-houses, and mountain ranges : postal, money order and Sale Price: $39.95 |
|
This book, "Geographical encyclopaedia of New South Wales : including the counties, towns, and villages within the colony, with the sources and courses of the rivers and their tributaries : ports, harbours, light-houses, and mountain ranges : postal, money order and", by Hanson, William, of Sydney, N... |
 |
Port Sanilac Lighthouse on Lake Huron, Michigan, USA Photographic Poster Print by Alison Jones, 18x24 List Price: $29.99 Sale Price: $29.99 |
|
Port Sanilac Lighthouse on Lake Huron, Michigan, USA is digitally printed on archival photographic paper resulting in vivid, pure color and exceptional detail that is suitable for any museum or gallery display... |
 |
Port Isabel, Texas LIGHTHOUSE Suncatcher Window 11x22 Glass Panel Framed Sale Price: $69.95 |
|
** PURCHASE by 12/15 for CHRISTMAS DELIVERY! ** Wood-framed in high-quality Wisconsin hardwood, this panel of art glass measures 11.5" wide x 22.5" high, and comes with frame-top hooks & chain for hanging... |
 |
Rembrandt Charms Port Boca Grande Lighthouse, Florida Charm, 10K Yellow Gold Sale Price: $238.00 |
|
Please note that product images are enlarged to show detail. The actual item is 0.642 - (approx. 5/8 in.) inches long and 0.753 - (approx. 3/4 in.) inches wide. The Port Boca Grande Lighthouse: Florida Charm, 10K Yellow Gold is hand-polished with a High Polish finish... |
 |
Necklace Heart Charm Lighthouse Crest Anchor Sale Price: $29.97 |
|
Product Number: 030-513846460 Shine bright and share what you love (or who you love?) in this head-turning and stylish necklace. Featuring a heart-shaped personalized pendant, this custom jewelry has a high-quality, easy-to-use clasp... |
 |
Wallmonkeys Peel and Stick Wall Decals - Lighthouse at the Entrance to Nassau Port - 18"W x 12"H Removable Graphic Sale Price: $30.99 |
|
WallMonkeys wall graphics are printed on the highest quality re-positionable, self-adhesive fabric paper. Each order is printed in-house and on-demand. WallMonkeys uses premium materials & state-of-the-art production technologies... |