GENERAL ENGINEERING AND APPLIED SCIENCESSTRENGTH OF MATERIALSProblem Set: To be pass on Wednesday next week.1. A 30 m long aluminum bar is subjected to a tensile stress of 172Mpa. Find the elongation if E= 69116Mpa. ANS: 7.46cm2. A cast-iron column with annular cross section supports an axial compressive load of 250kN. Determine the inside diameter of the column if its outside diameter is 200mm and the limiting compressive stress is 50Mpa. ANS: 183.4 mm3. A water tank is 8m in diameter and 12m high. If the tank is to be completely filled, determine the minimum thickness of the tank plating if the stress is limited to 40Mpa. ANS: 11.77mm

4. Determine the length of the shortest 2-mm diameter bronze wire which can be twisted through two complete turns without exceeding a shearing stress of 70MPa. Use G=35Gpa. ANS: 6.28 m

5. A helical spring is made by wrapping steel wire 20mm in diameter around a forming cylinder 150 mm in diameter. Compute the number of turns required to permit an elongation of 100 mm without exceeding a shearing stress of 140MPa. Use G = 83 GPa. ANS: 13.83 turns

6. A 150m steel rod with a cross-sectional area of 300 mm2 is suspended vertically from one end. It supports a load of 20kN at the lower end. If the unit mass of steel is 7850kg/m^3 and E = 200GPa, compute the total elongation of the rod. ANS: 54.33 mm

7. A helical steel spring composed of 20 turns of 20 mm diameter wire on mean radius of 80 mm supports a load of 2kN. Determine the elongation in the spring. Use G = 83GPa. ANS: 98.7mm

8. What is the maximum torque that can be applied to a hollow circular steel shaft having 100 mm outside diameter and 70 mm inside diameter without exceeding a shearing stress of 60MPa or a twist of 0.5 deg/m? Use G = 83GPa. ANS: 5.4 kN-m

9. A 3m long hollow steel shaft must transmit a 25 kN-m torque. The total angle of twist in this length is not to exceed 2.5 and the allowable shearing stress is 90MPa. What is the outside diameter of the shaft? Use G = 85GPa. ANS: 146 mm

10. An iron column with annular cross-section has an outer diameter of 200mm and is subjected to a 74kN force. If the allowable compressive stress is 10MPa, compute the thickness of the wall.ANS: 12.56 mm