Math Is Fun Forum

Oran2009

Member

Registered: 2016-06-13

Posts: 21

Vectors Question - Direction and Speed

Problem:

A skiff leaves a dock and heads toward a house across the river. The house is at a bearing of

from the dock. There is a 1 mile per hour current blowing due east. Determine the speed and direction the skiff would have to maintain so that the skiff's actual speed is 4 miles per hour and moving directly towards the house.

I know you can solve this with vectors and using trigonometry, but how would I do this?

*You can use the law of sines to find the direction, but what about the speed? Is it just 4 miles?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Vectors Question - Direction and Speed

hi Oran2009

I have shown the resultant vector (DH) with a double arrow.  It is made up from two components, DP and PH.  You know DH and PH so you can use trig. to get DP.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob