... Basic Calculations 69 Determine the difference in force, Ib Differential force, Ib = downward force, Ib - upward force. lb Differential force, lb = 77371b - 84301b Differential force ... output for 95% efficiency: 18 Formulas and Calculations Capacity = 0. 1963ft3/linft 183.35 f) Capacity, Iinft/ft3 = ~ ID, in.2 Example: Determine the capacity, linft/ft3, for a ... 54 Formulas and Calculations 62.4649 + 75.25 - 94 - 35.819 1.0034 - 0.418494 - 0.0595 x= 7.8959 0.525406 x= x = 15.1 lb of hematite per sk of cement used Calculations for...