potential energy well for a 2.0 kg particle (the function U(x) has the form bx2 and the vertical axis scale is set by us = 2.0 J).
(a) If the particle passes through the equilibrium position with a velocity of 85 cm/s, will it be turned back before it reaches x = 15 cm?
(b) If yes, at what position, and if no, what is the speed of the particle at x = 15cm?