Company Apple Inc. purchased machinery for $50,000 cash on January 1, 20X1. The machinery is expected to have a useful life of 5 years and a salvage value of $5,000. Calculate the annual depreciation expense using the straight-line method and prepare the journal entry to record the depreciation for the first year. Explain the straight-line method of depreciation and its significance in allocating the cost of long-term assets over their useful lives.