Mechanical Engineering Answers

A wooden log of 0.8 m diameter and 6 m length is floating in a river water. Find the depth of wooden log in water when the sp. gr. Of the wooden log is 0.7.

In a triple riveted butt joint with two equal cover strips, having zigzag

arrangement of riveting the thickness of the plate 10 mm. Consider allowable

tensile, crushing and shear stress are 100 MPa, 150 MPa and 80 MPa

respectively. Calculate: - (i) diameter of rivet and (ii) pitch of rivet joint.

A simple flange coupling has to transmit 50 KW at 250 RPM. . Assume torque

to be 20 % more than the full load. Calculate (a) Shaft diameter (b) Key

Dimensions and (c) number & size of Bolts. The stresses are as under, For

Shaft & Key [σt] = 75 N/mm2, [] = 50 N/mm2,[σc] = 120 N/mm2 For Bolt

[]= 40 N/mm2

Air at a pressure of 101.3 k Pa and 288.8 K enters inside a tube having an inside diameter of 12.7 mm and a length of 1.52 m with a velocity of 24.4 m/s. Condensing steam on the outside of the tube maintains the inside wall temperature at 372.1 K . Calculate the convection coefficient of the air. ( Note: This solution is trial and error. First, assume an outlet temperature of the air. )

Determine The Saturated Temperature, Saturated Pressure And Enthalpy For Water At Specific Volume Of Saturated Vapor At 10.02 m^3/kg.

A piston-cylinder device contains 0.1 m3 of liquid water and 0.9 m3 of water vapor in equilib­rium at 800 kPa. Heat is transferred at constant pressure until the temperature reaches 350°C.

(a) What is the initial temperature of the water?

(b) Determine the total mass of the water.

(c) Calculate the final volume.

(d) Show the process on a P-v diagram with respect to saturation lines.

Four kg of water is placed in an enclosed volume of 1m^3. Heat is added until the temperature is 150∘C. Find

( a) the pressure,

(b )the mass of vapor, and

(c) the volume of the vapor.

During the execution of a reversible nonflow process, the work done is -165 kJ. If the initial volume is 0.845 cu.m. and the pressure varies as p = -730V + 690 kPaa, where V is in cu.m.

The exhaust gases on leaving cylinders were passed through an exhaust gas calorimeter and raised the temperatures of 215kg of water from 15°c to 61°c.determin break thermo efficiency

A piston of 46 mm diam moves concentrically in a cylinder of 50 mm diam. The cylinder is filled with water and when the piston moves into the cylinder the water flows through the gap surrounding the piston. If the velocity of the piston is 75 mm/s relative to the cylinder, what is the velocity of the flow through the gap.