A particle starts sliding down a frictionless inclined plane. If S_n is the distance traveled by it from time t = n - 1 sec to t = n sec, the ratio S_n / S_n+1 is

A particle is acted by a force F = kx, where k is a +ve constant. Its potential energy at x = 0 is zero. Which curve correctly represents the variation of potential energy of the block with respect to x