Q. Suppose the x-velocity of the car at any time t is given by the equation = 60 / + (0.5

3
)
2
(a) Find the change in x-velocity of the car in the time interval 1 s to 3 s. (b)
Find the average x-acceleration in this time interval.

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