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.
Do you mean how long do they need to keep individual time cards...clearly a base payroll record....but worthless after no time...and it would cost zillions in storage fees to keep them very long. So, they really need to keep them for as long as anyone involved might care. As a rule of thumb, 7 to 10 years is standard.utside of the period, and the taxpayer doesn't have to provide it. I suspect your asking about your own payroll records from an employer. They are required to timely (by 1/31 following the year end) to have provided you with your W-2.