Why do sound waves move faster through the ground than through the air? a. particles of matter are packed more loosely in the ground than in the air. b. particles of matter are packed more tightly in the ground than in the air. c. air doesn’t contain any particles of matter to transmit sound waves. d. the elevation of the ground is lower than the elevation of the air space.

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f