[OSAMA2006]

ممكن تساعدوني في حل هذا السؤال من الوحدة الثالثه:
A particle in the xy-plane is attracted toward the origin by a force F =k/y, inversely proportional to its distance from the x-axis. Calculate the work done by the force when the particle moves from the point x =0, y =a to the point x =2a, y=0 along a path which follows the side of rectangle consisting of a segment parallel to the x-axis from x =0, y=a to x=2a, y=a, and a vertical segment from a latter point to the x-axis.
B) Calculate the work done by the same force when the particle moves a long an ellipse of semiaxis a, 2a. (Hint: set x= 2a sin , y= a cos)