Mechanical Engineering Answers

For the solid steel shaft shown (G = '77 GPa}, determine the “v angle of twist at A. (b) Solve part (a), assuming that the steel shaft is hollow with a 30-mm enter diameter and a 20-mm inner diameter.

Calculate the volume of a parallelopiped whose vertices are given by (0,0,0),

(2,1,3),(3,2,4) and (4,2,1).

an isa 200×100×10 angle is welded to steel plate by means of fillet welds the angle is subjected to static force of 150 kN and the permissible shear stress for the weld is70kN. determine length of welds at top and bottom .l1=100mm,and l2=200mm

An air refrigerator works between the pressure limits of 1 bar and 5 bar. The temperature of air entering the compressor and expansion cylinder are 10oC and 25oC respectively. The expansion and compression follow the law pv1.3=constant. Find the following

A multi-disc clutch has three discs on the driving shaft and two on the driven shaft. The inner diameter of the contact surface is 120 mm. The maximum pressure between the surface is limited to 0.1 N/mm2. Find the outer diameter for transmitting 25 kW at 1575 rpm. Assume uniform wear condition and coefficient of friction as 0.3.

A full journal bearing of 50 mm diameter and 100 mm long has a bearing pressure of 1.4 N/mm2. The speed of the journal is 900 r.p.m. and the ratio of journal diameter to the diametral clearance is 1000. The bearing is lubricated with oil whose absolute viscosity at the operating temperature of 75°C may be taken as 0.011 kg/m-s. The room temperature is 35°C. Find : 1. The amount of artificial cooling required, and 2. The mass of the lubricating oil required, if the difference between the outlet and inlet temperature of the oil is 10°C. Take specific heat of the oil as 1850 J / kg / °C.

A multi disc clutch, steel on bronze is to transmit 20 kW at 1440 rpm. The clutch is to be operated in oil with the coefficient of friction 0.08 and the average pressure is 0.3 MPa. Space limitation permits only 230 mm as outside diameter of the clutch. Assuming uniform pressure, determine: (i) Actual axial force required (W’) (ii) Actual maximum pressure (p’max) (iii) Actual average pressure (p’ave) Ratio of (Ri/Ro) can be chosen between 0.5 and 0.75 suitably and logically

Two tanks A and B contain 1 kg of air at 1 bar, 50oC and 3 bar, 50oC when

atmosphere is at 1 bar, 15oC. Identify the tank in which stored energy is

more. Also find the availability of air in each tank.

an lvdt is used to measure the axial deformation of the simple bar of fig. 10.3. the uncertainty in this measurement is ±0.025 mm. a steel bar is to be used to measure a force of 1100 n with an uncertainty of 1 percent. determine a suitable diameter and length of rod for this measurement, assum- ing the rod dimensions will be known exactly

A single cylinder petrol engine has a volume compression ratio of 4:1, takes in a mixture of fuel and air at a temperature of 20°Cand its pressure is 101kPa. If the pressure at the end of the compression stroke is 1.5MPa what will be its final temperature?