An engraving machine costs $28,000 with a residual value of $1,900. the machine is
expected to have a useful life of 150,000 hours. the machine is used 15,000 hours the
first year and21,000 hours the second year. calculate the depreciation expense for
year two and show your work.

Depreciation is the process of a business body to allocate an assets cost over its duration of services or useful time in use. You can use the formula of Straight line method which the quotient of the difference of original cost of assets and the scrap value and the estimated life of assets. So in calculating the engraving machines has a 1.5k of yearly depreciation so 3K and more is the 2 year depreciation of its use. 

It will take him 5 days