Friday, February 12, 2010

Mechanics Maths Boat Exercises Maths Alevel Mechanics, Boat's Journey, Vectors, Bearings Problem?

Maths Alevel Mechanics, Boat's Journey, Vectors, Bearings Problem? - mechanics maths boat exercises

A boat travels at a speed of 11 knots to the east. The current flows in a direction of 210 ° at a speed of 5 knots. What is the resultant velocity of the boat.

With a chart with the cosine law to solve this problem, it is fairly simple. . the solution is 7.123 knots.

http://i166.photobucket.com/albums/u94/j ...

That is my plan, but would for some reason used the book for cos30 and cos60. WHY ?!?!?!?!

Please give us jobs - and an explanation (preferably with a description of a picture or a drawing one) that I will explain why using cos30 that could replace cos60.

Best answer: 5 star, the solution is 7.123 knots.

2 comments:

someone else said...

//////////////
Speed currect dir =- 2.5 y = 5sin210
.............................. to x = dir 5cos210 =- 4.33
INY boat speed dir = 0
...................... "x dir = 11
add
Net-x dir = 6.67
NET DIR Y =- 2.5
result = sqrt (6.67 ^ 2 2.5 ^ 2) = 7.123
dir = Reservoir =- 2.5/6.67
k = 20.5
so that DIR is 249.5deg

vect said...

Janson is right

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