WRITTEN EXERCISES 308. 1. Express 15° C. in the Fahrenheit scale. SOLUTION. = -Since 1° C. g° F. (§ 306), 15° C. 15 × ° F. above the freezing point, that is, above 32° F. 2. Express 59° F. in the centigrade scale. SOLUTION. Since 59° F. means 59° - 32° or 27 Fahrenheit degrees above the freezing point of water, and since each Fahrenheit degree above the freezing point is equivalent to § of a centigrade degree above 0° C., 59° F. = §(59 – 32) degrees centigrade = 15° C. 3. Blood heat is about 98° F. thermometer register blood heat? Where would a centigrade 4. Olive oil freezes at 50° F., and mercury at Express these freezing points in the centigrade scale. - 37.9° F. - 10° F., 5. When the temperature falls from 15° F. to how many Fahrenheit degrees does it fall? how many centigrade degrees? 6. Water is heaviest at 4° C. Express this temperature in degrees Fahrenheit. 7. Milk is pasteurized by heating it to 681° C. and keeping it at that temperature for a certain time. Express the temperature in the Fahrenheit scale. 8. During the ascent of a mountain in Switzerland the temperature fell from 25° C. to 5° C. How many Fahrenheit degrees did it fall? 9. During a 5-year period the highest average monthly temperature in Manila was 28.7° C. in June; and the lowest was 25° C. in January. Express these temperatures in the Fahrenheit scale and find the difference between the highest and the lowest. LUMBER MEASURE It is 309. The unit of lumber measure is the board foot. defined as a board 1 foot long, 1 foot wide, and 1 inch thick. Then the number of board feet in a board 1 inch (or less) thick is the same as the number of square feet of surface in one side of the board. A board 1 foot wide and 12 feet long contains 12 board feet, if it is 1 inch (or less) in thickness. For brevity the word "foot" is used instead of board foot, and " thousand feet" or "M" instead of thousand board feet. 310. When lumber is more than 1 inch thick, the number of board feet is obtained by multiplying the number of feet in length by the number of feet in width, and that product by the number of inches in thickness. 7 A board 12 ft. long and 8 in. wide contains 12 × ft., or 8 ft., if it is 1 in. (or less) thick; if it is 2 in. thick, it contains 2 × 8 ft., or 16 ft.; if 11⁄2 in. thick, 1 x 8 ft., or 12 ft. Instead of 12 ft. by 8 in. by 2 in. we may write 12′ x 8′′ × 2′′. WRITTEN EXERCISES 311. Find the number of feet in the following: 15. The pasting table used by a paper hanger consisted of four-inch white pine boards 6 feet long and 10 inches wide. How many feet of lumber did it contain? 16. For a combination bookcase, 45 feet of plain oak were used at $30 per M, 10 feet of 3-ply oak at $95 per M, and 8 feet of quartered oak at $60 per M. This cost was of the cost of the materials used. Find the entire cost of materials. 17. A slab of ash 38 inches long, 11 inches wide, and 2 inches thick makes 4 baseball bats, which sell at 8 each at the mill. How many feet of ash are required to fill the order of a sporting goods company for baseball bats to the value of $46.08? 18. Find the cost, at $16 per M, of this lumber for a shed designed to cover an acre of growing pineapples: 463 posts 4" x 4" x 9' 3900 boards 1" x 3" x 16' (roof) 450 boards 1" x 12" x 16' (sides) 19. A man who had 16 rows of celery, each row 160 feet long, blanched the celery by placing boards on both sides of each row and banking earth against them. The boards were 1 inch thick and 14 inches wide. Find the cost at $21 per M. 20. To preserve the celery in winter it was placed in trenches 16 inches deep, the walls of which were lined with rough 1-inch boards. There were 40 trenches, each 60 feet long. What was the cost of the lumber at $12 per M? 21. Find the cost of this lumber for a house, at $20 per M: sills 4" x 8', total length 192'; 10 posts 4" x 7" x 24'; ties and plates 4" x 6', total length 522'; 70 beams 2'' × 8'' × 15'; 60 beams 2" x 8" x 22'; 15 rafters 3" x 5" x 20'. 22. In making checkers of a certain size, a piece of lumber 12' x 12'' x 11'' was sawed into 7 strips, each foot of strip making 20 checkers. How many feet of lumber were used to make enough checkers to fill 2800 boxes holding 30 each? ROOFING AND FLOORING 312. The unit of roofing and flooring is an area of 100 square feet called a square. The average shingle is about 18 inches long and 4 inches wide. When laid "4 inches to the weather," the exposed surface of 1 shingle is (4 × 4) sq. in., or sq. ft. Consequently it takes 900 shingles to cover a square, but to allow for waste 1000 shingles per square are often estimated. There are 250 shingles in a bunch. WRITTEN EXERCISES 313. 1. The roof of a house was 38' long and it was 30' from the ridge to the eaves on each side. How many pieces of slate 9" wide were required to cover the roof, if they were laid 6'' to the weather? 2. Find the weight of slate on the roof, if a square foot weighed 4 pounds. 3. The roofer averaged 2 squares in 10 hours. If he received 35¢ per hour, how much did he receive for laying the roof? 4. Find the cost of the slate at $5.75 per square. 5. Adding $2.75 for hardware and breakage, what was the entire cost of the roof? 6. How many bunches of common shingles should be purchased to cover a roof 80' x 32', estimating 4 bunches per square? (A part of a bunch cannot be purchased.) 7. Find the cost of the roof at $6 per square. 8. Good cypress shingles may be laid 41 inches to the weather. How many, to the nearest shingle, are required to cover a square? How many bunches must be purchased to cover a roof 38' x 35', estimating 875 shingles per square? THIRD PROG. AR. -12 9. How many pieces of maple flooring, 14' long and 21" wide when laid, are required for the floor of a room 12' x 14'? Since 10. The boards are " thick. they were 3" wide before being tongued 2 K---3" and grooved, they are sold as boards 3" wide. Find the cost of the flooring at $35 per M. 11. How many days will be required to lay a mosaic tile floor in a room 48' × 36', if the tiler can lay in a day 20 sheets of tile, each sheet 2' x 1'? 12. What will be the cost of the floor at $1.55 per square foot? PLASTERING AND PAINTING 314. The unit of plastering, painting, and kalsomining is usually the square yard. Laths are 4 feet long and there are 50 or 100 in a bundle. In this book a bundle means 100 laths. Custom is not uniform as to allowances for openings and baseboard. Consequently to avoid misunderstandings, a written contract should be made. WRITTEN EXERCISES 315. The second story of a cottage consisted of 4 bedrooms. Each was 18' x 12' and 9' high, with 2 windows, each 3'6" x 6' and 1 door 3' x 7'. Find the following, deducting openings: 1. The number of laths required, if 1500 cover 100 sq. yd. 2. The cost of putting on the laths at 6 per sq. yd. 3. The number of days it will take a plasterer to lay on three coats, if he can plaster 144 sq. yd. of first coat per day, as much of second coat, and as much of third coat. 4. The cost of plastering the rooms at 33 per sq. yd. |