0
Mechanical Engineering
Mechanical Engineering is a branch of engineering that encompasses the generation and application of heat and mechanical power and the design, production, and use of machines and tools. Mechanical engineering involves application of the principles of dynamics, control, thermodynamics and heat transfer, fluid mechanics, strength of materials, materials science, electronics, and mathematics.
10,989 Questions
What is the Cheapest and common shaft material?
cheapest material is Mild steel having very good properties of shaft.
What will happen when 25 percent petrol mixed with diesel in diesel engine?
It'll probably be OK. As long as there's enough diesel to properly lubricate the injection pump then no problems.
Unit weight of steel bars according to their diameter?
The unit weight of steel is 7850kg per cubic meter, so the unit weight of different bars can be calculated by multiplying the volume of 1m length of bar with the unit weight of steel.
It can also be calculated simply by dividing the square of the diameter of bar in mm by 162.
Diameter of bar unit weight calculation.
8 0.395kg/m w=8x8/162
10 0.617kg/m w=10x10/162
12 0.889kg/m w=12x12/162
16 1.580kg/m w=16x16/162
20 2.469kg/m w=20x20/162
25 3.858kg/m w=25x25/162
Fire detection and protection system description?
A system which is networked with extinguishing and detection devices to ensure that the danger of fire is low. Smoke/Heat detectors, sirens, bells, sounders and call points are in place to detect any fire and alert you if there is the need to evacuate. A person can manually activate the call point if they discover a fire. When the fire alarm sounds, extinguishing apperatus such as sprinklers, CO2 gas release will activate, in order to quickly put the fire to a halt.
Welding is the process of joining two similar or dissimilar metals by heating and melting it by adding some additives on that to make the joint perfect...
Well, assuming that you are talking about headlights, the low beams are the dimmest settings for the drive headlights, while high beams are the brightest setting.
What things have mechanical energy?
Clocks, Watches, Locks, Ferris wheels, there are TONS of possibilities! :)
How many vertebrae do pigs have?
The number of presacral vertebrae in pigs varies from 26 to 30.
S. Berge Genetical Researches on the Number of Vertebrae in the Pig
J Anim Sci 7: 233-238, 1948.
N. Borchers, N. Reinsch and E. Kalm The number of ribs and vertebrae in a Piétrain cross: variation, heritability and effects on performance traits J. of animal breeding and genetics 121(6):392-403, 2004.
:
There are several genes believed to influence this.
S. Mikawa, T. Hayashi, M. Nii, S. Shimanuki, T. Morozumi, and T. Awata Two quantitative trait loci on Sus scrofachromosomes 1 and 7 affecting the number of vertebrae
J Anim Sci 83: 2247-2254, 2005.
.
What is the difference between hot finish seamless pipe and cold drawn seamless pipe?
A cold drawn seamless pipe has better dimensional tolerance, a higher surface finish and better mechanical properties than an equivalent hot finish seamless pipe. For applications that can make use of the thinner pipe walls and closer tolerances, a cold drawn seamless pipe is the better option.
Can young modulus of elasticity equals modulus of rigidity?
For isotropic materials
G = E/ (2(1+u)
where u = poisson ratio
How do you calculate weight of mild steel when sectional area given?
Calculate the volume first by multiplying the cross sectional area with length.
Multiply the volume with density of mild steel which will give the weight.
The density of Mild steel is 7850 kg/ m3
e.g
Calculate the weight of 2 m rod having cross sectional area of 5 m2
Volume = 2x5 = 10 m3
Weight = 10 x 7850 = 78500 kg
Be specific that same units are used all around the calculations.
Is S275JR superior to ASTM A 36?
Yes you can use. The Chemical and Mechanical properties are similar.
How do you calculate the cross sectional area of a tube?
The volume of a sphere refers to the number of cubic units that will exactly fill a sphere. Its metric unit is the liter.
+++
You can also use cubic linear dimensions (cubic metre and its divisions), depending really on what is the most sensible for the application.
What does bar pressure stand for and psi?
In the SI system the pressure unit is the Pascal (after the French maths genius) which is defined as 1 Newton per square meter. This is a very small unit. Atmospheric pressure is about 105 Pascals, and this is called the Bar. You have probably seen in weather forecasts the pressure given in millibars, the normal atmospheric pressure is 1000 mb, and the equal pressure contours on the weather maps give the millibar figure. These contours are called Isobars, as they are lines of constant pressure.
Psi stands for pounds per square inch, which is I imagine easier to grasp, and is probably more widely used in the US. In Europe and the UK, in power plants and other industries, the pascal - kilopascal - bar units are used. I was brought up on psi and had to convert mid life, I have got used to bars but find kilopascals don't come easily.
It is useful to remember that 1 bar = 14.5 psi. You will also come across psig, which just means pressure aboveatmospheric, it stands for psi gauge, as a gauge normally reads zero at atmospheric pressure. If you see psia, this means psi absolute, the pressure above vacuum, where atmospheric pressure = 14.5 psia.
What do mechanical engineers do?
It depends on the area they go into. Mechanical engineering is such a big field it can vary from design, manufacture, maintenance, inspection and many other things. You can be a mechanical engineer that never picks up a tool or like me, you can spend your days performing maintenance on 50 year old pumps!
How can you calculate weight of ms sheet For example?
Take the volume in inches and multiply it by the density.
Example: 2" x 2" x 1/4" thick flatbar.
2*2*0.25=1 cubic inch
cubic inch multiplied by density (0.2836#/cubic inch)
1*.2836 = 0.29#
The comparison between CNC and conventional system?
Repeatability on a conventional machine relies on the skill of the operator
and the quality of the machine.
A programmed CNC machine will exactly repeat complete requirements
for machining a given component to a very high degree of accuracy,
usually 0.0008 mm.
This can then be stored in the machine's computer memory or on a tape
or disc etc, which can then be used to repeat the exact machining cycle at a
later date.
The construction of a CNC machine is much stronger, more rigid, and will
Repeatability on a conventional machine relies on the skill of the operator
and the quality of the machine.
A programmed CNC machine will exactly repeat complete requirements
for machining a given component to a very high degree of accuracy,
usually 0.0008 mm.
This can then be stored in the machine's computer memory or on a tape
or disc etc, which can then be used to repeat the exact machining cycle at a
later date.
The construction of a CNC machine is much stronger, more rigid, and will
vibrate less than a conventionalmachine.
The accuracy of machining with a conventional machine tool is dependent on
the ability of an operator to read the dials or indicator scales correctly, and to
take account of any backlash when manually adjusting the position of the cut,
feed etc.
How does a pneumatic cylinder act with water in the air?
Air cylinder or air rams consists of a tube with a sealed base, a piston attached to a rod and a gland to seal the tube and rod where the rod exits the barrel. This assembly is called the cylinder or ram.
The ram is ported in the top and bottom to allow pressurized air to enter and exit the cylinder. This moves the piston which is attached to the rod and created the movement.
Cylinders are usually stationary at one end and the rod is attached to a moving part. This is called a double-acting cylinder because pressurized air can be let into both sides of the cylinder to create movement.
A single-acting cylinder relies on gravity to extend or retract it as it is only ported on either the top or bottom side of the cylinder.
What are the differences between the four major types of roads?
The difference between the four roads are; the expressway is designed to carry huge amounts of traffic quickly over long distances. Arterial roads carry moderate amounts of traffic over shorter distances. Collector roads move traffic from local roads to areterial roads. Local roads that are smaller and narrower than arterial roads.
Do you use a helmet or safety goggles when arc welding?
yes
'
+++
You do NOT use "goggles" when arc-welding. You use a proper face-shield (mine is the auto-darkening type), and you should not expose any skin to the arc's intense UV radiation.
Diffence between ferritic stainless steel and martensitic stainless steel?
Ferritic stainless steel are magnetic, containing no nickel and not hardened by heat treatment. For example 409 and 430 stainless steel
Martensitic stainless steel are also magnetic and containing no nickel but hardened by heat treatment. For example 410 and 420 stainless steel
Does heat treatment increase the carbon content in carbon steel?
Heat increases the potential energy and temperature of steel.
