(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A helicopter velocity relative to the ground is flying south for exactly .75hours. A wind blows and the helicopter ends up 30 Km in a southwesterly position away from her starting point. the helicopter speed relative to the ground is 50km/hour. What is the direction and the speed of the wind?

2. Relevant equations

Vhg + Vwg = Vha

d1 + d2 = d3

Speed x time = distance

Law of cosines

Law of sines

3. The attempt at a solution

I've gotten to this point without using matrices and without using polar vector coordinates.

Two triangles seem to appear similar when there are no units...however they are not.

One triangle was formed from using just speeds.

40 km/hour = Speed of helicopter relative to air

50 km/hour = speed of helicopter relative to ground

W = speed of wind relative to the ground

Another triangle was formed from using just distances

37.5 km = distance to the south

30 km = distance to the southwest

D = distance in the direction of the wind

There is a multiple of .75 hours from speed of wind to the distance traveled in direction of the wind.

The two triangles form a proportion of 4/5. THIS PROPORTIONALITY IS DIFFERENT FROM .75 !!!

Help

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# Homework Help: Difficult relative velocity problem

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