A physics professor leaves her house and walks along the sidewalk toward campus. After 5 min it starts to rain, and she returns home. Her distance from her house as a function of time is shown in ?Fig. E2.10. At which of the labeled points is her velocity (a) zero? (b) constant and positive? (c) constant and negative? (d) increasing in magnitude? (e) decreasing in magnitude?

Answer: From the Fig. E2.10. We can answer the following question. 1) At point (iv) the velocity is zero, because from here the velocity starts to be negative means it goes to zero and then negative. 2) At point (i) the velocity is maximum, because it’s a straight line graph which shows constant increase in velocity. 3) Point (v) shows a constant decrease in velocity , a Linear graph which means its decreasing or negative as the direction is opposite to that of the increasing velocity. 4) Point (ii) there is a steep graph, it indicates increase in magnitude of velocity. 5) At point (iii) fi we look at the slope of the graph its very small and also the graph is going down which shows that the magnitude of velocity is decreasing.