13. Zelda stands at the top of a 50.0 meter high cliff. She throws a stone horizontally off of the cliff at a speed of 18.0 m/s. a. How much time passes until the stone hits the flat plains below? b. What is the stones final horizontal velocity right before impact? c. What is the stone's final vertical velocity right before impact? d. What is the stone's final velocity (combined horizontal and vertical) at the moment of impact? Be sure to give magnitude and direction