Consider four different oscillating systems, indexed using =1,2,3,4. each system consists of a block of mass moving at speed on a frictionless surface while attached to an ideal, horizontally fixed spring with a force constant of . let denote the displacement of the block from its equilibrium position. order the systems from largest total mechanical energy to smallest.

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.