1. What force is required to punch a hole 50 mm in diameter through a 16-mm-thick aluminum-alloy plate? An average stress of 265 MPa will cause this material to shear.
2. How wide a gap should be allowed between the 50-ft-long paving slabs of concrete in a street so that the slabs will touch each other at a temperature of 90 degrees F? The pavement is laid at a temperature of 65 degrees F. What would be the compressive stress in the slabs if the temperature rose to 110 degrees F? (E for concrete is 3 000 000 psi.)
3. A wire made of copper alloy is 4.5 m long and 1 mm in diameter. It is stretched 14.5 mm by a load of 340 N. What is the modulus of elasticity of this alloy?
4. The total elongation of a square wrought iron bar 50 mm on a side and 3 m long is 1.5 mm. What is the load?
5. Find the total elongation and the stress in a 1-in-diameter AISI 1045 steel rod 12 ft long under a pull of 12 000 lb.
6. Two A36 plates, each 10 in wide and V2 in thick, are connected by %-in A 325 steel bolts (threads occur at the shear plane) to form a lap joint. Based on shear, how many bolts will be needed if the pull on the joint is 15 000 lb? Use the AISC code, friti on-type connection.
7. Two plates forming a lap joint carrying 5000 lb in tension are connected by two A307 steel bolts. What should be the diameter of the bolts based on the AISC code? Consider shear only.
8. If an 18-in Class 20 cast-iron vertical pipe is subjected to a head of 140 ft of water, what thickness of plate will be required? Assume varying stress conditions.
9. Three unfinished planks are nailed to an unfinished plank, as shown in Fig. Prob. 10-4 in the textbook. How far is the centroid above the base?
10 . Find the volume of the rim of a flywheel 6 ft in diameter if the rim is 12 in wide and 8 in thick.
11. Locate the centroid of the T section in Fig. Prob. 10-1 in the textbook from point 0.
12. Determine the unknown reactions and sketch and label the shear force and bending moment diagrams for the beam of Prob. 11-16 in the textbook, except that an external counterclockwise couple of 25 000 ft - lb is applied at a point 4 ft from the wall.
13. A simple beam that is 150 by 200 mm in rough-sawn cross section and 3 m long carries a concentrated load of 36 lcINT at the center. Find the largest bending stresses developed at sections 0.9, 1.5, and 2.4 m from the left end.
14. A wooden beam 12 ft long is supported at the ends. If the rough-sawn cross section is 6 by 8 in and the allowable bending street is 1100 psi, what total uniform load can the beam support?
15. In Prob. 12-2 in the textbook, if the allowable bending stress is 1200 psi and the rough-sawn cross section of the beam is 6 by 9 in, what is the maximum length of the span if the total uniform load is 6000 lb?