On December $31,2024,$ a company sold a machine for $$20,000$ that it had been using in its operations. The machine was originally purchased on January $1,2021,$ for $$40,000,$ and it has been depreciated for four full years under the straight$-$line method with no salvage value and a $10-$year useful life. What is the amount of the loss on the sale of the machine?$\backslash$