The curvature in Mars is such that its surface drops a vertical distance of 2.0 meters for every 3600 meters tangent to the surface. In addition, the gravitational acceleration near the surface is 0.4 times near the surface of Earth. What is the speed a golf ball would need to orbit Mars near the surface, ignoring the effects of air resistance? First let me tell you that I am teaching myself physics, forgive me if I sound completely clueless. I am not quite sure how I should start. Should I use Newtons law of Universal gravitation F=Gm1m2/r^2. Circular motion equations or Hooke's law? Any other clues to get me started would be appreciated. Thanks.