2.10 . 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? Figure E2. 10 x (m) IV 400 III 300 200 V II 100 I t (min) O 1 2 3 4 5 6 7 8