Engineering Answers

two clean parallel glass plate, 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 δ=0.0730 N/m?

a square block weighing 1.1kn and 250 mm on an edge slides down an incline on a film of foil 6.0μm thick. assuming a linear velocity profile in the oil and neglecting air resistance, what is the terminal velocity of the block? the viscosity of oil is 7 Mpa-s angle of inclination to 20°.

(a) if 12m³ of nitrogen at 30°c and 125kpa abs is permitted to expand isothermally to 30m³, what is the resulting pressure?

(b) what would the pressure and temperature have been if the process had been isentropic?

air is kept at a pressure of 200kpa and a temperature of 30°c in a 500-l container. what is the mass of the air?

calculate the density of water vapor at 350kpa abs and 20°c if its gas constant is 0.462kpa-m³/kg-°k.

what would be the weight of 13kg mass on a planet where the acceleration due to gravity is 10m/s²?

Listed below is a combination of stresses acting at a point and referred to axes x and y in an elastic material. Using Mohr’s circle of stress determine the principal stresses at the point and their directions for each combination. 

i) sigma x=-60 N/mm^2, sigma y=-36N/mm^2, shear stress (xy) =5N/mm^2

ii) sigma x=30 N/mm^2, sigma y=-50N/mm^2, shear stress (xy) =30N/mm^2

At a particular point in a structural member a two dimensional stress system exists where sigma x=60N/mm^2 sigma y=-40N/mm^2 and shear stress (xy) =50N/mm^2 if young's modulus =200000N/mm^2 and poisson's ratio =0.3 calculate the direct strain in the x and y directions and the shear strain at the point.

Direct stresses of 120 N/mm^2 (tension) and 90 N/mm^2 (compression) are applied at a particular point in an elastic material on two mutually perpendicular planes the principal

stress in the material is limited to 100 N/mm^2(tension) calculate the allowable value of shear stress at the point on the given planes determine also the value of the other principal stress and the maximum value of shear stress at the point using Mohr's circle

A member ABCD is subjected to point loads P1,P2,P3, and P4 calculate the force P3 necessary for equilibrium if P1, = 120 kN, P2, = 220 kN and P4, = 160 kN. Determine also the. net change in the length of the member. Take E = 200 GN/m²