Light gates may be used to measure the speed of projectiles, such as arrows shot from a bow. English longbows made of yew in the 1400s achieved launch speeds of 60 m/s. Determine the relationship between light gates and the accuracy required for sensing the times when the light gate senses the presence of the arrow.

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