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A 4.5-kg mass is given an initial velocity of 14 m/s up an incline that makes an angle of 37o with the horizontal. When its displacement is 8.0 m, its upward velocity has diminished to 5.2 m/s.

I'm confused with directions of the velocity. In the solution they used the equation

vf

^{2}=vi

^{2}+2*a*d

anyway to find 'a' they subtracted (14

^{2}-5.2

^{2})/(2*8)

So doesn't this mean initial velocity and the upward velocity are parallel since they are being subtracted. I assumed the initial velocity would be parallel to the incline and the upward velocity completely vertical and thus i would have to 5.2/sin37.

When you read the question, what direction would you assume? Maybe it's right and i'm just mixing up the axis?