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.
4. Seven Year Rule for Record Retention(general rule). The rules on how long to keep financial records varies depending on what you are saving. For up to date tax filings, 7 years is a safe rule of thumb.Some people might say that is too long, but it is easier to follow this rule than to have to keep track how long you should keep different info.We suggest you keep tax returns for the life of your company. Scan them and save them both on and off site..or up to date tax filings, 7 years is a safe rule of thumb. Some people might say that is too long, but it is easier to follow this rule than to have to keep track how long you should keep different info. We suggest you keep tax returns for the life of your company. Scan them and save them both on and off site..