A cannon fires a 9 lb projectile with an initial velocity of 60 m/s, at an angle of 15 degrees. Assuming that air resistance performs 2.50 kJ of work against the projectile, what is the maximum height of the projectile? What is the ratio of the maximum height obtained with neglecting air resistance to the maximum height attained with air resistance? NOTE: Assume that the zero point of the potential energy is level with the ground, and the height of the cannon above the ground is negligible.