A particle of mass 0.50 kg moves along the x-axis with a potential energy whose dependence on x is shown below. (a) What is the force on the particle at x=2.0,5.0,8.0,and 12 m? (b) If the total mechanical energy E of the particle is −6.0 J, what are the minimum and maximum positions of the particle? (c) What are these positions if E=2.0J? (d) If E=16J, what are the speeds of the particle at the positions listed in part (a)?