Civil and Environmental Engineering Answers

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.

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?

The following consecutive readings were taken with a level and a 4-metre leveling staff on a continuously sloping ground at common intervals of 30 m:

0.855 (on A), 1.55 m, 2,335, 3.825, 0.455, 1.380, 2.055, 2.855, 3.455, 0.585, 1.015, 1.850, 2.755, 3.845 (on B).

The RL of A was 380.500. Make entries in a level book and apply the usual checks. Determine the gradient of AB.

A 30 m steel tape was standardised at a temperature of 20^o C and under a pull 5 kg. The tape was used in catenary to fix a distance of 28 m between two points at 40^o C and under a pull of 5 kg. Given that the cross-sectional area of the tape = 0.02 cm², total weight 470 g. Young’s modulus of steel = 2.1 X 10⁶ kg/cm, and coefficient of linear expansion = 11 x10^-6per ^oC, (a) find the correct distance between the points, and (b) find the value of pull for which the measured distance would be equal to the correct distance.

A battery having a voltage source of cos t is connected to a series circuit on which the

inductance is 0.75 henry and the resistance is 15 ohms. Determine the current i at any time t if the

initial current is zero.