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.
When sorting through dusty file boxes or the pile of papers on your desk, itâs easy to become confused as to which records you need to keep and those you should shred. Here are some guidelines to help you determine how long to keep records: 1  Tax Records: Seven years, to be safe. 2  Pay Stubs: One year. 3  Bank Statements: One year. 4  Credit Card Statements: At least 45 days. 5  Medical Records: At least a year, but often longer. 6  Insurance Records: Keep policy information for the life of the policy plus an additional five ...