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3 years ago

Name the main classes of polymer and define their characteristic properties

Engineering

1 answer:

Svetlanka [38]3 years ago

8 0

Answer:

Polymers are the naturally occurring or synthetic macromolecules that are composed of repeating subunits, called monomers.

The three main classes of polymers are: thermoplastic, thermosetting, and the elastomers.

Thermoplastic polymers have linear bonding. These polymers can be melted again and thus can recycled.

Thermosetting polymers have cross-linked bonding. These polymers decompose when heated and thus can not be remelted and recycled.

Elastomers have linear bonding with some cross-linking. These polymers extreme elastic extensibility and thus can revert back to its original shape after deformation, without causing any permanent damage.

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cricket20 [7]

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The power generated by a wind farm is not constant because of irregular wind patterns.

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3 years ago

A cold air standard gas turbine engine with a thermal efficiency of 56.9 % has a minimum pressure of 100 kP

Aleks04 [339]

Answer:

a) 5.2 kPa

b) 49.3%

Explanation:

Given data:

Thermal efficiency ( л ) = 56.9% = 0.569

minimum pressure ( P1 ) = 100 kpa

<u>a) Determine the pressure at inlet to expansion process</u>

P2 = ?

r = 1.4

efficiency = 1 - [ 1 / (rp) $\frac{r-1}{r}$ ]

0.569 = 1 - [ 1 / (rp)^0.4/1.4

1 - 0.569 = 1 / (rp)^0.285

∴ (rp)^0.285 = 0.431

rp = 0.0522

note : rp = P2 / P1

therefore P2 = rp * P1 = 0.0522 * 100 kpa

= 5.2 kPa

b) Thermal efficiency

Л = 1 - [ 1 / ( 10.9 )^0.285 ]

= 0.493 = 49.3%

4 0

2 years ago

Locate the centroid y¯ of the composite area. Express your answer to three significant figures and include the appropriate units

german

Answer:

Please see the attached Picture for the complete answer.

Explanation:

4 0

2 years ago

If a worksite includes more than one set of management and workers, who should have access to the information, training, and con

Elden [556K]

Answer:

In a work site with more than one set of management and workers the Health and safety officers in each set should have access to the information, training and controls needed to avoid workplace accidents

Explanation:

The primary aim of a health and safety officer in a workplace is to prevent accidents,injuries and work-related sickness from occurring in the work site by creating and implementing health and safety policies according to international standards and also ensure that these policies are implemented by the sets of management and workers/staffs of the work site. to achieve these they therefore should have access to the information,training and controls needed to avoid workplace accidents

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3 years ago

Read 2 more answers

A vertical piston-cylinder device initially contains 0.2 m3 of air at 20°C. The mass of the piston is such that it maintains a c

Ann [662]

Answer:

Amount of air left in the cylinder=m $_{2}$ =0.357 Kg