6. (08.02 HC) W(t) = -sin 1- The water level of a certain body of water is changing at a rate of 2 inches per hour, where t represents hours since 12 a.m. Part A: Using correct units, explain the meaning of liz W(f) dt in terms of the context of this problem. (1 point) Part B: Write the integral that represents the number of inches that the water level changes from 10 a.m. to 3 p.m. (2 points) Part C: Use your calculator to evaluate your integral from Part B. Explain the meaning of the answer in terms of the context. (3 points) Part D: What is the average hourly number of inches that the water level changes for this lake in one day? (4 points)