007 Review Problem - Length of wire

Problem 7
If a piece of brass 8 by 6 by 12 in. is drawn out into a wire 1/30 in. in diameter, what will be the length of the wire?
 

006 Review Problem - Area illuminated by light placed in front of the globe

Problem 6
A light is placed 5 ft. from the center of the globe 3 ft. in diameter. Find the area of the illuminated portion.
 

005 Review Problem - Weight of gravity dam

Problem 5
If the gravity whose cross section is shown in the figure weighs 150 lb. per cu. ft., find the total weight of a section of a dam 50 ft. long.
 

005-gravity-dam.gif

 

004 Review Problem - Size of a column in Fingal's Cave

Problem 4
In Fingal’s Cave, on the Island of Staffa (Hebrides, Scotland), the walls are formed by basaltic prismatic columns varying in height from 18 to 36 ft. These columns, mostly hexagonal, are so perfect as to suggest the hand of man. One of the vertical columns is 29.3 ft. in height and has a base of 4.7 sq. ft. What is its volume?
 

003 Review Problem - Sphere melted into cylinder

Problem 3
Two spheres of lead, of radii 2 and 3 in., respectively, are melted into a cylinder of revolution of radius 1 in. Find the altitude of the cylinder.
 

002 Review Problem - Great wall of China moved to the equator

Problem 2
The great Chinese wall is said to be 1500 miles long, 20 ft. high, 15 ft wide at the top, and 25 ft. wide at the bottom. If it were possible to build with this material a wall around the earth at the equator, of a uniform thickness of 4 ft., how high could it be made? (The equator is approximately 24,900 miles long.)
 

001 Review Problem - Weight of a brass water pipe

Problem 1
Find the weight of a brass water pipe 20 ft. long whose inside diameter is 1.5 in. and whose thickness is 1/4 in., if brass weighs 520 lb. per cu. ft.
 

Properties of common materials

Material Unit weight
(kN/m3)
Density
(kg/m3)
Specific
Gravity
Aluminum 26.095 2660 2.66
Brass 81.423 8300 8.3
Brick 19.62 2000 2.0
Cast iron 70.632 7200 7.2
Concrete 23.544 2400 2.4
Copper 87.407 8910 8.91
Earth (dry) 12.557 1280 1.28
Earth (wet) 17.266 1760 1.76
Glass 25.408 2590 2.59
Ice 8.829 900 0.9
Lead 111.540 11,370 11.37
Mercury 133.416 13,600 13.6
Oil 8.829 900 0.9
Water (fresh) 9.81 1000 1.0
Water (sea) 10.104 1030 1.03
Wood (hard) 7.848 800 0.8
Wood (soft) 4.709 480 0.48

Problem 422 - Right-triangular Truss by Method of Sections

Problem 422
Refer to the truss described in Problem 412 and compute the force in members BD, CD, and CE by the method of sections.
 

412-right-triangular-truss.gif

 

Problem 421 - Cantilever Truss by Method of Sections

Problem 421
Use the method of sections to compute for the force in members DF, EF, and EG of the cantilever truss described in Problem 411 and Fig. P-411.
 

411-cantilever-truss.gif

 

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