Mohr Company purchases a machine at the beginning of the year at a cost of $$36,000.$ The machine is depreciated using the units$-$of$-$production method. The company estimates it will use the machine for $5$ years, during which time it anticipates producing $80,000$ units. The machine is estimated to have a $$4,000$ salvage value. The company produces $10,000$ units in year $1$ and $7,000$ units in year $2.$ Depreciation expense in year $2$ is: