A car's horn is honking at a constant frequency. as the car is driving away from you the pitch you hear will be what is heard by the driver of the car A. lower than
B. higher than
C. the same as
D. exactly twice

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