A bungee cord can stretch, but it is never compressed. When the distance between the two ends of the cord is less than its unscratched length L0, the cord folds and its tension is zero. For simplicity, neglect the cord's own weight and inertia as well as the air drag on the ball and the cord. A bungee cord has length L0 = 33 meter when unscratched; when it's stretched to L > L0, the cord's tension obeys Hooke's law with "spring" constant 39 N/m. To test the cord's reliability, one end is tied to a high bridge of height 94 meter above the surface of a river) and the other end is tied to a steel ball of mass 75 kilogram. The ball is dropped off the bridge with zero initial speed. Fortunately, the cord works and the ball stops in the air a few meters before it hit the water - and then the cord pulls it back up. The acceleration of gravity is 9.8 m/s2.
Determine the ball height above the water surface at this lowest point of its trajectory.
Answer in units of m.
Find the tension of the bungee cord when the ball is at its lowest point?
Answer in units of N.