Civil and Environmental Engineering Answers

A purchasing agent plans to buy some new equipment for the mailroom. Two manufacturers have

provided bids. An analysis shows the following:

Manufacturer Cost Useful Life (years) End-of-Useful-Life

Salvage Value

Speedy $2500 7 $250

Allied 2600 7 425

The equipment of both manufacturers is expected to perform at the desired level of (fixed)output. For a

7-year analysis period, which manufacturer’s equipment should be selected? Assume 7% interest and

equal maintenance costs.

Using the method of joints, determine

the force in each member of the truss

Determine maximum diameter of hole that can be punched through a plate of 10mm thick,if the punch can withstand a compressive stress of 500mpa and ultimate shear stress of 200mpa

Calculate the i) specific weight, ii) mass density, iii) specific gravity and iv) specific volume oil the oil having a volume 4 500 litres and a weight of 40 kN.

If a liquid has a viscosity of 0.051 poise and a kinematic viscosity of 0.14 stokes, calculate its specific gravity.

Oil flows from a tank through a 50 mm diameter pipe. If the average velocity is 1.3 m/s, determine how long it will take for 2500 kg of oil to flow out. Take S.G (oil) = 0.78

In an experiment on a venturi meter installed in a 300 mm diameter pipe, the mercury in the differential U-tube manometer connected to the venturi meter deflects 73 mm when 73 l/s of water is flowing in the pipe. If the diameter of the throat of the venturi is 150 mm, calculate Cd for the venturi

A 250 mm diameter pipe carrying 30 l/s of water suddenly enlarges to 400 mm diameter. Find the headloss due to the sudden enlargement.

𝑦" + 3𝑦′ + 2𝑦 = 𝑓(𝑡); 𝑦(0) = 0, 𝑦′(0) = 1

𝑓(𝑡) ቄ

1, 0 ≤ 𝑡 < 3;

0, 𝑡 ≥ 3.

Find the discharge through a trapezoidal notch which is 1 m wide at the top and 0.4 m at the bottom and is 300 mm in height. The head of water on the notch is 200 mm. Assume Cd for the rectangular portion is 0.62 while for the triangular portion is 0.6.