This may seem like a silly question, so pardon in advance. I was working through some practice 2D Kinematic word problems, and I was wondering whether my approach is wrong.
I know how to calculate the acceleration in the x-direction and the velocity in the x-direction, but up until now, I've been assuming that the displacement ($x_f-x_i$) is equal to the length of the horizontal leg of the triangle formed by the ramp. Is it in fact the length of the hypotenuse? This doesn't seem right to me. The reason I'm confused is because of this practice problem. My intuition tells me that they solved this problem incorrectly.