Question

the figure shows the power consumption in san francisco for a day in september (p is measured in megawatts; t is measured in hours starting at midnight). (a) what was the power consumption at 6:00 a.m.? 500 mw what was the power consumption at 6:00 p.m.? 740 mw (b) when was the power consumption the lowest? t = 4 h (c) when was the power consumption the highest? t = 12 h (d) find the net change in the power consumption from 9:00 a.m. to 7:00 p.m. -100/9 mw

Explanation:

Step1: Identify time - points

9:00 A.M. corresponds to \(t = 9\) and 7:00 P.M. corresponds to \(t=19\).

Step2: Read power values from graph

From the graph, when \(t = 9\), \(P(9)\approx700\) MW and when \(t = 19\), \(P(19)\approx600\) MW.

Step3: Calculate net - change

The net change in power consumption \(\Delta P=P(19)-P(9)=600 - 700=- 100\) MW.

Answer:

\(-100\) MW