Lohman's Lumber purchased a piece of equipment six years ago for $360,000. It expects a salvage value of $60,000 at the of the equipment's useful life of 20 years.

1. Calculate the monthly and annual depreciation expense.
2. What is the accumulated depreciation in year 6, and the net book value for the equipment?

• What if Lohman's Lumber changed the equipment's useful life from 20 years to 15 years. What impact does this have on the Lohman's depreciation expense and the asset's net book value in year 6?

• Why is depreciation considered a non-cash expense?