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3 years ago

For a refrigerator, COP<1 a) True b) False

Engineering

1 answer:

WINSTONCH [101]3 years ago

4 0

Answer:

False

Explanation:

COP is Coeficient of performance, it relates useful heat moved with work consumed, it is used in refrigerators and heat pumps.

For refrigerators the useful heat is the one extracted from the cold reservoir. Therefore:

$COP = \frac{Tcold}{T.hot - Tcold}$

This often exceeds 1.

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GMA MIG weiding is a

Dvinal [7]

Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a welding process in which an electric arc forms between a consumable MIG wire electrode and the workpiece metal(s), which heats the workpiece metal(s), causing them to melt and join.

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3 years ago

A 0.91 m diameter corrugated metal pipe culvert (n = 0.024) has a length of 90 m and a slope of 0.0067. The entrance has a squar

NikAS [45]

Answer:

HW=1.71m

Explanation:

Please kindly check attachment for the step by step solution of the given problem.

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3 years ago

5. The pin support at A allows _______. Select the one that applies. (a) displacement in the x direction (b) rotation about its

soldier1979 [14.2K]

Answer: Diagram associated with your question is attached below

5) B

6) C

Explanation:

5) The pin support at A allows ; Rotation about its central axis

This is because pin supports does not allow the translation of its structural member in any direction i.e. y or x but only rotation about its axis

6) The support at B does not allow displacement in y direction

This is because roller support allows displacement only in the direction that they are situated and in this case it is the x - direction

7 0

3 years ago

What could happen in the aviation

Alina [70]

Answer:

Yes

Explanation:

7 0

3 years ago

What are the units or dimensions of the shear rate dv/dy (English units)? Then, what are the dimensions of the shear stress τ= μ

swat32

Answer:

1) Dimensions of shear rate is $[T^{-1}]$ .

2)Dimensions of shear stress are $[ML^{-1}T^{-2}]$

Explanation:

Since the dimensions of velocity 'v' are $[LT^{-1}]$ and the dimensions of distance 'y' are $[L]$ , thus the dimensions of $\frac{dv}{dy}$ become

$\frac{[LT^{-1}]}{[L]}=[T^{-1}]$ and hence the units become $s^{-1}$ .

Now we know that the dimensions of coefficient of dynamic viscosity $\mu$ are $[ML^{-1}T^{-1}]$ thus the dimensions of shear stress can be obtained from the given formula as

$[\tau ]=[ML^{-1}T^{-1}]\times [T^{-1}]\\\\[\tau ]=[ML^{-1}T^{-2}]$

Now we know that dimensions of momentum are $[MLT^{-1}]$

The dimensions of $Area\times time$ are $[L^{2}T]$

Thus the dimensions of $\frac{Moumentum}{Area\times time}=\frac{MLT^{-1}}{L^{2}T}=[MLT^{-2}]$

Which is same as that of shear stress. Hence proved.

4 0

3 years ago