4. A 1.50 kg snowball is fired from a cliff 12.5 m high. The snowballs initial velocity is 14.0 m/s. directed 41.0\" above the horizontal. Using the conservation of mechanical energy, calculate the speed of the snowball as it reaches the ground below the cliff. 5. An 80.0 kg skydiver jumps out of a balloon at an altitude of 1000 m and opens the parachute at an altitude of 200 m. (a) Assuming the total retarding force on the diver is constant at 50.0 N with the parachute closed and constant at 3 600 N with the parachute open, nd the skydiver's speed when he lands on the ground. (13) Do you think the skydiver will be injured? Explain. (c) At what height should the parachute be opened so that the final speed of the skydiver when he hits the ground is 5.00 mls