Engineering Answers

Given: A steel rod (A= 150 mm2) is stretched between

two fixed points with a tensile load of 5000 N at 200C.

a.) What will be the stress at -200C?

b.) At what temperature will the stress be zero?

Assume α = 11 .7 μm/m0C, and E = 200 Gpa

To condition the air in an office building in the winter, 1000 cm3 of moist air at 101 kPa and22oC enters the process. The air leaves the process at 98 kPa. How many kg of water

vapour are added to each kg of wet air entering the process? Partial pressure of water in

entering air is 1.31 kPa; Partial pressure of water in leaving air is 18.14 kPa.

An open tube is attached to a tank as shown. If the water rises to a height of 800mm in the tube, what are the pressure a and b of the air above water? Neglect capillary effects in the tube

A solid steel bar of diameter d1 = 25.0 mm is enclosed by a steel tube of outer diameter d3 = 37.5 mm and inner diameter d2 = 30.0 mm (see figure). Both bar and tube are held rigidly by a support at end A and joined securely to a rigid plate at end B. The composite bar, which has a length L = 550 mm, is twisted by a torque T = 400 N-m acting on the end plate.

(a) Determine the maximum shear stresses Ƭ1 and Ƭ2 in the bar and tube, respectively.

(b) Determine the angle of rotation ϕ (in degrees) of

the end plate, assuming that the shear modulus of

the steel is G = 80 GPa.

(c) Determine the torsional stiffness kT of the

composite bar.

If the kinematic viscosity of water at S.TP is 1:0038 x 10 m²/a and the mass density is 998.23 kg/m³, calculate its absolute viscosity

If the kinematic viscosity of water at S.TP is 1:0038 x 10 m²/a and the mass density is 998.23 kg/m³, calculate its absolute viscosity

A steel shaft ABCD having a total length of 1.5 m is made of three lengths AB , BC and CD each 0.5 m long. AB and BC are solid shaft having diameter 50 and 75 mm respectively , CD is hollow with outside and inside diameters 75 and 50 mm respectively . when an axial torque of 5 kNm is transmitted from one end of the shaft to the other , the total angle of twist is 1.2° , Determine the maximum shear stress and modulus of rigidity of the material.

A triaxial stress element as shown in Figure has σx = 40 MPa, σy = –20 MPa, σz = –10 MPa, τxy = 5 MPa, τyx = –1.5 MPa, τzx = 2.5 MPa. Answer following questions:

Find the principal stresses using a numerical method (i.e., using Eigen values method) and draw the resulting Mohr’s circles. (You can use Scientific Calculator for calculating eigen values of the stress matrix)

Draw the resulting Mohr's circles.

A high strength steel of yield strength: 1200 Mpa in form of wide plate contains a Semi elliptical surface crack of depth 10mm and length 100mm and located at centre of plate. The plate is subjected to tensile stress at 90° angle to crack. The plate was found to break in service in unstable manner resulting completely flat fracture surface. the size of plastic zone measured at minor crack tip just at the instant of fracture to be 0.25 mm. what could be have the fracture toughness

find the angle the surface tension film leaves the glass for a vertical tube immersed in water if the diameter is 0.25 inch and the capillary rise is 0.08 inch. use δ=0.005 lb/ft.