1.A light bulb emitting 1750 lm of luminous flux shines on a book that is 3.0 m away. a. What is the illumination on the book?
b. In general terms, how will illuminance change as a person in the room moves the book closer to the light bulb? How does this illustrate an inverse-square relationship?

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