Engineering Answers

A continuous cable (diameter 6 mm) with tension force T is attached to a horizontal frame member at B and C to support a sign structure, Fig. 1. The cable passes over a small pulley at D. The wire is made of a copper alloy, and the stress-strain relationship for the wire is (a) Find the axial normal strain in the cable and its elongation due to the load W = 6.8 kN (b) If the forces are removed, what is the permanent set of the cable. Hint: Start with constructing the stress-strain diagram and determine the modulus of elasticity, E and the 0.2% offset yield stress.

In a Diesel engine inlet pressure and temperature are 1 bar and 17 oC respectively. Pressure at the end of adiabatic compression is 35 bar. The ratio of expansion i.e. after constant pressure heat addition is 5. Calculate the heat addition, heat rejection and the efficiency of the cycle. Assume Cv = 0.717 kJ/ kg K, 𝛾=1.4 

Deduce an expression for Air-standard efficiency of Otto cycle. A diesel engine has a

compression ratio of 22 and cut-off take place at 7% of the stroke. Find the efficiency

A mixture of benzene and toluene containing 40 mole % of benzene is to be separated to give a product of 90 mole % benzene at top and a bottom product with not more than 10mole % benzene. Using an average value of 2.4 for relative volatility of benzene relative to toluene, calculate the number of theoretical plates required at total reflux. Also calculate the minimum reflux ratio, if the feed is liquid and is at its boiling point

The open tank contains two different liquids as shown below. Determine the total pressure at elevation zero.

Two clean parallel glass plates, separated by a distance d = 1.5 mm, are dipped in a bath of water. How far does the water rise due to capillary action, if σ = 0.0730 N/m?

Benzene at 20°C has a viscosity of 0.000651 Pa-s. What shear. stress is required to deform this fluid at a strain rate of 4900 s-1?

Calculate the density, specific weight, and volume of chloride gas at 25 °C and pressure of 600 000 N/m2 absolute.

In a piston-and-cylinder apparatus the initial volume of air is < 90 – 120 > L at a pressure of < 100 – 130 > kPa and temperature of 26 °C. If the pressure is doubled while the volume is decreased to < 50 – 60 > L, compute the final temperature and density of the air.

 If < 2.2 – 4.3 > m3 of substance weighs <20 - 40 > kN, calculate the following.

a.) Specific weight

b.) Density

c.) Specific gravity