Wind blowing across suspended power lines may

cause the power lines to vibrate at their natural

frequency. This often produces audible sound

waves. This phenomenon, often called an

Aeolian harp, is an example of

(1) diffraction (3) refraction

(2) the Doppler effect (4) resonance

tube or goog with be a great resource to with that question

answer: i'm not sure which is which for i get confused on it all the time but i can tell you that the answer lies with the convex and concave devices. i hope this you. have a good day and best of luck to you!

explanation:

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west