Energy is the capacity to do work, and power is the rate at which energy is used or consumed. Therefore, if E(t) is the energy function for a a. Estimate the power at t = 10 hr. Choose the correct answer below. system, then P(t) = E'(t) is the power function. A unit of energy is the kilowatt-hour; the corresponding units for power are kilowatts. The graph shows the energy demand function for a small community over a 25-hr period. Complete parts a through c. O A. The power at t= 10 hr is approximately - 386 KW. 450 O B. The power at t= 10 hr is approximately 15 kW. O C. The power at t = 10 hr is approximately 386 kW. 400- O D. The power at t= 10 hr is approximately - 15 kW. 350- Estimate the power at t= 20 hr. Choose the correct answer below. Energy (KWh) A. The power at t= 20 hr is approximately - 390 KW. 250 OB. The power at t= 20 hr is approximately 390 KW. 2004 C. The power at t= 20 hr is approximately 15 kW. 10 20 Time (hrs) D. The power at t= 20 hr is approximately - 15 kW. b. At what time (s) on the interval [0,25] is the power zero? Choose the correct answer A. The power is zero at t= 3 and t = 15 hr. OB. The power is zero at t= 22 hr. O C. The power is zero at t= 9 and t = 21 hr. OD. The power is zero at t= 10 hr. c. At what time(s) on the interval [0,25] is the power at its maximum? Choose the corred A. The power reaches its maximum at times t= 9 and t = 21 hr. OB. The power reaches its maximum at times t= 3 and t= 15 hr. OC. The power reaches its maximum at t = 9 hr. D. The power reaches its maximum at t = 17 hr