HELP! Please! (1 Viewer)

[lvella10]

An aeroplane takes off from an airport and flies on a bearing of 220 degrees for a distance of 570 km. Calculate how far south of the airport the aeroplane is ...

Now I know this should be easy, But I just can't wrap my head around drawing this ..

 

[lvella10]

To me it equates to 570cos(220) But that gives me a negative amount?

 

[lvella10]

Or is it 570sin(50) .. the 50 being the only unknown angle ?
Are both of these methods right if I converted the Cosine answer into a positive??

 

[barbernator]

your answer is correct, but distance is just the absolute value of your answer, as using angles to calculate distance gives us a vector solution (i.e. magnitude and a direction) but we only want a magnitude, so just take the positive solution. Also, for a simpler solution, just draw a triangle for the direction of travel, and then your angle will just be 570cos(40) which is the same as yours but then you don't have to worry about + and -

 

[lvella10]

Thankyou! +1