Problem 911
A concrete dam has the profile shown in Figure P-911. If the density of concrete is 2400 kg/m3 and that of water is 1000 kg/m3, determine the maximum compressive stress at section m-n if the depth of the water behind the dam is h = 15 m.
Problem
A grade of -5% is followed by a grade of 1%, the grades intersecting at the vertex (Sta. 10 + 060). The change of grade is restricted to 0.4% in 20 m. Compute the length of the vertical parabolic sag curve in meters.
Problem
A tensile load of 8000 kg elongates a 1-m long square rod by 1 mm. Steel modulus of elasticity is 2 × 106 kg/cm2. What is the dimension of a side of the rod?
Problem
A job posted at jobstreet.com offered a starting salary of \$40,000 per year and guaranteeing a raise of \$1600 per year for the rest of 5 years. Write the general term for the arithmetic sequence that models potential annual salaries.
A. an = 38,400 + 1600n
B. an = 33,400 + 2600n
C. an = 36,400 + 1400n
D. an = 34,400 +1800n
Problem
A given alloy contains 20% copper and 5% tin. How many pounds of copper and of tin must be melted with 100 lb of the given alloy to produce another alloy analyzing 30% copper and 10% tin? All percentages are by weight.
A. 20.5 lb copper and 4.5 lb tin
B. 17.5 lb copper and 7.5 lb tin
C. 19.5 lb copper and 5.5 lb tin
D. 18.5 lb copper and 6.5 lb tin