If 20 waves of water pass you in 5.0 s and the waves are 2.0 m long, how fast are they moving? 1.0 m/s 4.0 m/s 2.0 m/s 8.0 m/s

The correct answer is 8 m/s

Explanation:

I took the test and this was the right answer

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