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.
1 How long to keep records: Keep the records for at least three months. 2  Review that all the purchases are correctly entered in your bank and credit card statements. 3  Review your monthly bills.4  If there is a discrepancy, then keep the document until you resolve the problem. How long to keep records: Keep the records for at least three months. 2  Review that all the purchases are correctly entered in your bank and credit card statements. 3  Review your monthly bills.