Mechanical Engineering Answers

Oil, with 900 kg/m3 and 0.00001 m2/s, flows at 0.2 m3/s through 500 m of 200-mm diameter
cast iron pipe. Determine the head loss.

A body weighs 1000 lbf when exposed to a standard earth gravity g = 32.174 ft/s2. (a) What
is its mass in kg? (b) What will the weight of this body be in N if it is exposed to the
moon’s standard acceleration gmoon = 1.62 m/s2?

A Piston and cylinder machine contains a fluid system which process through
a complete cycle of four processes. During the cycle, the sum of all heat
transfer is -170KJ. The system completes 100 cycles/min .complete the
following table showing the method for item and completes the net rate of
work output in KW

It is desired to transmit 90 kW by means of a solid circular shaft roating at 3.5 rad/s. the allowable shearing stress it 45 MPa. Find the required shaft diameter.

A cooper tube 55 mm in outside diameter and of will thickness 5 mm fits loosely over a solid steel circular bar 40 mm in diameter. The two members are fastened together by two metal pins each 8 mm in diameter and passing transversely through both members, one pin being near each and of the assembly. At room temperature the assembly is just stress free when the pins are in position. The temperature of the entire assembly is then raised 40°C. Calculate the average shear stress in the pins. For cooper E=90GPa, a=18x10¯6/°C;for steel E=200GPa, a=12x10¯6/°C.

Consider a simply supported beam carrying the concentrated and uniform loads shown in Fig. 7-41.Select the height of a 2-cm-wide rectangular section to resist these loads based upon a working stress in either tension or compression of 120 MPa

A plane element is subject to the stresses o,x= 60 MPa, y= -60 MPa, and txy = 0. Determine analytically the maximum shearing stress existing in the element. What is the direction of the planes on which the maximum shearing stresses occur?

A plane element is subject to the stresses x= 50 MPa ard y=-50 MPa.From Mohr's cirele determine the stresses acting on a plane inc lined at 20 to the -axis.

A man of mass 80 kg is travelling in a lift which is moving upwards. If the lift
comes to rest from a velocity of 2 m/s in a 2 seconds, find the force exerted by the
man on the lift floor if the deceleration is constant. What would be the reaction if the
lift were travelling downwards?

Two kg of steam with a quality of 30% is heated at a constant pressure of 300KPa until the
temperature reaches 600 °C. Calculate the work done by the steam