The following formula is used to calculate the specific gravity of a material. Where SG = specific gravity, Ï = density of the material (kg/m3), ÏW = density of water ( kg/m3). The reference density of water at 4oC (39oF) is used as the reference as these are the conditions of maximum density.
Most business owners donât know how long they should hold on to old records. According to the IRS, hereâs how long you should keep those records: Permanently: 1  general ledgers and journals. 2  payroll records, including W-2s, 940s, 941s. 3  year-end financial statements.4  tax returns and supporting documents. 5  articles of incorporation, bylaws, meeting minutes, etc. 6  retirement plan records.ost business owners donât know how long they should hold on to old records. According to the IRS, hereâs how long you should keep those records: Permanently: 1  general ledgers and journals. 2  payroll records, including W-2s, 940s, 941s. 3  year-end financial statements. 4  tax returns and supporting documents.
Personal Finance December 08, 2013. While the basic rule is to keep records for three years after you have filed your return, that period is lengthened if any information is questioned by the Internal Revenue Service (IRS). Then it becomes three years after the final resolution of the item(s) in question for records related to the item(s).