An airplane with an airspeed of 430 km/h is heading directly northwest. It encounters a wind from the south blowing at 142 km/h. What is the resultant ground speed of the airplane?
The answer is 540 km/h but I have no idea how

Question

An airplane with an airspeed of 430 km/h is heading directly northwest. It encounters a wind from the south blowing at 142 km/h. What is the resultant ground speed of the airplane?
The answer is 540 km/h but I have no idea how

phi · Answer

draw two vectors representing the airplane and the wind

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phi · Answer

It helps to know the degrees of a compass, and that northwest is 45 degrees "off of" north

to find the resultant, add "head to tail"
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