Mechanical Engineering

First class levers are like see-saws. The fulcrum (turning point) comes between the effort and the load. So if you push down on the effort the load goes up. With second class levers the load comes between the effort and the fulcrum. This is good for catapulting things. Third class levers have the effort between the load and the fulcrum. An example would be a fishing rod. The fish on the end is the load, your hand on the rod is the effort and the hand at the end is the fulcrum.

hair dryer, cars ,lawnmower ,generator ,computer ,pool ,cleaner ,tv ,plane ,cell phone ,fans ,heaters ,remote contrl car ,boat

For DC:

Permanent magnet brush motor; (uses fixed magnets for stator fields); toys and automotive use

Shunt field motor; (field winding has many turns of fine wire in parallel with armature) small machines;

Series field motor; (field winding has few turns of heavy wire in series with armature); high speed, high torque;

Compound field motor; (has both series and shunt fields); large machinery, general purpose workhorses;

Brushless DC motors (use electronics to switch stator windings on and off, and have permanent magnet rotors) small fans and light loads.

For single phase AC:

Split Phase induction motor (2 different windings connected to supply, cage type rotor) low torque, general purpose;

Capacitor Start induction motor; (As per split phase, but with capacitor in series with starting winding) high starting torque, general purpose;

Capacitor start, Capacitor run induction motor; (as per capacitor start, but different capacitors used for starting and running) high starting and running torque, quietest running;

Shaded pole induction motor; (run winding and copper or aluminium ring around part of iron core of stator) small, cheap motors, low torque;

Universal motor; (as per series DC motor above) high torque, high speed, poor speed stability.

For 2 or 3 phase AC (star or delta connected)

Polyphase induction motor (2 or 3 identical windings on stator, cage rotor) general purpose;

Wound rotor induction motor (2 or 3 identical windings on stator, wound rotor connected in star to 3 sliprings and external resistance unit) very high starting torque, low starting current;

Synchronous motor; (standard stator, and wound rotor connected to DC supply for 'excitation' of rotor field) constant speed, power factor correction.

GAUGE , is one inch thick of steel or metal.

So, take this one inch thick of steel sheet and cut it into 12 equal thickness sheets , you get a 12 gauge steel sheet.

Similarly, take this one inch thick of steel sheet and cut it into 14 equal thickness sheets , you get a 14 gauge steel sheet. and so on .

So, a 12 gauge steel sheet is thicker than 14 gauge , 14 is thicker than 16 , 16 is thicker than 18 and so on.

Wrong!!! See my discussion on this...

Type 316 is an austenitic chromiumnickel

stainless steel containing

molybdenum. This addition increases

general corrosion resistance, improves

resistance to pitting from chloride ion

solutions, and provides increased

strength at elevated temperatures. Properties

are similar to those of Type 304

except that this alloy is somewhat

stronger at elevated temperatures.

Corrosion resistance is improved, particularly

against sulfuric, hydrochloric,

acetic, formic and tartaric acids; acid

sulfates and alkaline chlorides.

Fineness Modulus is used to know the size of aggregate grains (Particles) for various measurements used in Civil Engineering.

To characterize the overall coarseness or fineness of an aggregate, a concept of fineness modulus is developed. The Fineness Modulus is defined as

Fineness Modulus =

Σ(Cumulative Retained Percentage)

100

To calculate the fineness modulus, the sum of the cumulative percentages retained on a definitely specified set of sieves needs to be determined, and the result is then divided by 100. The sieves specified for the determination of fineness modulus are No. 100, No. 50, No. 30, No. 16, No. 8, No. 4, 3/8", 3/4", 1.5", 3", and 6".

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The efficiency of a steam turbine is just the ratio of power out to power in, but if you want to be able to calculate it from the basic mechanical design, this is a specialised topic. In the link below is a general description of steam turbines, in the references and additional reading list there are some references that may help you.

Isometric drawings, 3-D representations, are drawn on an angle to the parallel to show how the finished product should look. All dimensions should be the same as if drawn flat (2 dimensional).

It will be often desirable to know the power which is being consumed in operating a lathe on certain work for which data is required. For most purposes this can be sufficiently approximated by calculating the power of the lathe from the width of the belt and its speed in feet per minute.

For such purposes it is usual among mechanical engineers to consider that a one-inch belt traveling a thousand feet per minute will transmit one horse-power. This will give us a key to the entire calculation.

Scientist do hybrid to pick up good qualities. So there are 2 things better in something they try to mix and make a best item. For Eg. some flower have good looks but no smell and other have great smell but dull look so they mix and try to make a flower with great look and smell together. what else

cooling and lubrication,filters,centrifuges,oil heaters,intake and exhaust

Mag rims get there name from what metal they are made from. Magnesium! It's is a very interesting metal. It's very light weight, strong and cheap. At the right temperature it melts like any other metal however if you get it to hot it burns. Like friken crazy! Anyways mag rims are made by melting magnesium and injecting it into a mold. After cooling the rims are then tooled to finish their look and function.

Likely not much until you learn to spell it. Until then,

it could be embarassing in conferences, etc.

0.0747 inch. or 1.89 mm

a generator

It is important to maintain a vacuum in a condenser if you want it to work well.

Knurling is a machining process normally carried our on a centre lathe. The act of Knurling creates a raised criss cross pattern on a smooth round bar that could be used as a handle, or something that requires extra grip

efficiency
The ratio of useful energy to total input energy is called efficiency. It refers to the percentage of the work input that is converted to work output.

Tensile Strength, Ultimate 7.00 - 20.0 MPa 1020 - 2900 psi

This is the strength in a pure tension test. For bending use:

Modulus of Rupture 0.00410 - 0.0276 GPa 0.595 - 4.00 ksi

source: http://www.matweb.com/search/DataSheet.aspx?MatID=211&ckck=1

The original Spinning jenny could spin eight spindles of yarn at a time, but as technology improved the most advanced Spinning jenny could spin one hundred twenty spindles at a time!

In Imperial standard (swg), 16 g is 0.064" (1.63mm) thick.

A shell and tube heat exchanger will have two fluids flowing through continuously. The fluid in the tube will typically be the important fluid, the fluid you are trying to heat or cool. The fluid in the shell will then be the fluid that is heating or cooling the the fluid in the tube.

Take a steam heat exchanger for example. Steam condenses in shell, while the the fluid in the tube picks up the heat from the steam. And in a perfectly efficient steam heat exchanger, all the heat lost from the steam would be recovered by the liquid in the tube.

But nothing is perfect. A little bit of the steam's heat makes the outer shell hot, and that in turn heats the room. Heat is lost from the steam into places other than the fluid in the tube. So efficiency measures how much of the heat lost by the shell fluid makes it into the tube fluid.

Efficiency (for heating) = Amount of Heat that went toward heating the fluid divided by the amount of heat that was lost by the heating fluid.

So an efficiency of 1 is perfect. For every 1 unit of heat absorbed by the tube fluid, we spent 1 unit of heat from the fluid in the shell fluid.

And if the efficiency is 0.9, or 90%, then for every 10 units of heat that the shell fluid lost, the tube fluid gained 9.

Sometimes efficiencies are as bad as 40%. In this case for every 10 units of heat lost by the heating fluid, 4 units are gained by the fluid.

A slightly different definition of efficiency applies to cooling:

Efficiency = Amount of heat lost by the tube fluid divided by the amount of heat gained by the shell fluid.

Same story, if the shell fluid gains 5 units of heat, and tube fluid loses 4, then the efficiency is 0.8 or 80%.

What is the difference between 'Open Loop' and 'Closed Loop'? A: When the engine is first started, and rpm is above 400 rpm, the system goes into 'Open Loop' operation. In 'Open Loop', the ECM will ignore the signal from the Oxygen (O2) sensor and calculate the air/fuel ratio based on inputs from the coolant and MAF sensors, but mostly from a pre-programmed table in the memcal. The system will stay in 'Open Loop' until the following conditions are met: 1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)

2. The coolant sensor is above a specified temperature about 40oC/104oF.

3. A specific amount of time has elapsed after starting the engine. The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.

the ASTM (american society for testing materials) website has some information on rocks and minerals

You need to take up to 4 years of calculus, as well as many science classes in physics and chemistry. Classes in algebra and trigonometry may be prerequisites for calculus.