A factory begins emitting particulate matter into the atmosphere at 8 am each workday, with the emissions continuing until 4 pm. The level of pollutants, P(t), measured by a monitoring station ½ mile away is approximated as follows, where t represents the number of hours since 8 am:
75t + 100 if 0 is less than or equal to t and less than or equal to 4
400 if 4 is less than t or less than 8
P(t) = -100t + 1200 if 8 is less than or equal to t or less than or equal to 10
-50/7 t + 1900/7 if 10 less than t or less than 24
Find the level of pollution at
(a) 9am (b) 11am
(c) 5pm (d) 7pm
(e) midnight (f) Graph y = P(t)
(g) From the graph in part (f), at what time(s) is the pollution level highest? Lowest?