An object is placed between two plain mirrors which make angle 45 degree with each other. distance between all adjacent images are equal to 20 cm. find distance between the object and each other mirror. how many images are formed.

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