ing with... AutoCAD 2021 Tutorial... X Intro Section I FUNDAMENTALS OF GENERAL MATHEMATICS 8. The bookkeeper for a small trucking firm finds the yearly depreciation of company vehicles. The bookkeeper uses the appraisal method of depreciation. Under this method, yearly depreciation is based on the fraction of the life of the vehicle used in 1 year. The following formula is used to compute yearly depreciation: Yearly depreciation - (Original cost - Trade-in value) x Number of miles driven in one year + Number of miles of life expectancy Find the yearly depreciation to the nearest dollar of each of the four trucks listed in Figure 3-40. Original Trade-In Truck Number of Miles Driven Cost Value in One Year Number of Miles of Life Expectancy Yearly Depreciation 1 $21,800 $3000 46,500 250,000 2 $16,075 $2650 51,200 200,000 3 $28,900 $3800 57,910 300,000 4 $36,610 $4350 60,080 350,000 FIGURE 3-40 9. Heat transfer by conduction is a basic process in refrigeration. In a refrigeration system a condenser transfers beat by conduction. Refrigerant gas enters a condenser at a high temperature. Heat is absorbed by water surrounding the tubing that contains the gas, and the gas is cooled. Refer to Figure 3-41. REFRIGERANT 3 DECIMAL FRACTIONS 157 10. This problem deals with heat transfer by conduction. A technician wishes to determine the surface area of metal (A) required to transfer 120,000 Btu per minute (H), where K = 1740, TD 95°F; and d = 0.093 inch. 60 XHXd XXTD Find A in square feet to 1 decimal place. 11. A series-parallel electrical circuit is shown in Figure 3-43 R R R Find Ry to 1 decimal place when: a. R 5.20 ohms, R. = 2.3 ohms. R, 0.8 ohm. R, = 3.4 ohms, R = 0.7 ohm. b. R₁ 08 ohm, R, = 3.4 ohms, R, 1.5 ohms, R, - 5.3 ohms, R-0.9 ohm. www Lim Lim FIGURE 3-43 12. A flat is to be ground on a 0.750-centimeter-diameter hardened pin. Determine the depth of material to be removed to produce a flat that is 0.325 centimeter long. Express the answer to the nearest thousandth of a centimeter. c--05 -0.5 x where C-depth of material to be removed (depth of cut) D= diameter of the pin F = length of the required flat 13. The inside dimensions of a gas tube boiler are given in meters as shown in Figure 3-44. A pipefitter must determine the approximate number of cubic meters (volume) of steam space in the boiler. Steam space is the space above the boiler water line. WATER LINE -0.55 STEAM SPACE 0-18 T FIGURE 3-44 L=5.2