In diving to a depth of 635 m, an elephant seal also moves 370 m due east of his starting point. What is the magnitude of the seal's displacement?

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

k2s for potassium sulphide