Part 1: Suppose that a machine had a units-of-production depreciation rate of $2 per operating hour and that the machine was used 20,000 hours the first year. Please calculate the depreciation for the first year and show what the journal entry would be.

Part 2: Can we assume that the first year's depreciation expense (calculated in question 2 above) will also be the depreciation expense for subsequent years? Why or why not?