25 In differential aeration corrosion, rich oxygenated parts are

Define the terms (a) thermal conductivity, (b) heat capacity and (c) thermal diffusivity

IceJOKER [234]

Explanation:

(a)

The measure of material's ability to conduct thermal energy (heat) is known as thermal conductivity. For examples, metals have high thermal conductivity, it means that they are very efficient at conducting heat. The SI unit of heat capacity is W/m.K.

The expression for thermal conductivity is:

$q=-\kappa \bigtriangledown T$

Where,

q is the heat flux

$\kappa$ is the thermal conductivity

$\bigtriangledown T$ is the temperature gradient.

(b)

Heat capacity for a substance is defined as the ratio of the amount of energy required to change the temperature of the substance and the magnitude of temperature change. The SI unit of heat capacity is J/K.

The expression for Heat capacity is:

$C=\frac{E}{\Delta T}$

Where,

C is the Heat capacity

E is the energy absorbed/released

$\Delta T$ is the change in temperature

(c)

Thermal diffusivity is defined as the thermal conductivity divided by specific heat capacity at constant pressure and its density. The Si unit of thermal diffusivity is m²/s.

The expression for thermal diffusivity is:

$\alpha=\frac{\kappa}{C_p \times \rho}$

Where,

$\alpha$ is thermal diffusivity

$\kappa$ is the thermal conductivity

$C_p$ is specific heat capacity at constant pressure

$\rho$ is density

6 0

3 years ago

Vector A extends from the origin to a point having polar coordinates (7, 70ᵒ ) and vector B extends from the origin to a point h

yaroslaw [1]

Answer:

13.95

Explanation:

Given :

Vector A polar coordinates = ( 7, 70° )

Vector B polar coordinates = ( 4, 130° )

To find A . B we will

A ( r , ∅ ) = ( 7, 70 )

A = rcos∅ + rsin∅

therefore ; A = 2.394i + 6.57j

B ( r , ∅ ) = ( 4, 130° )

B = rcos∅ + rsin∅

therefore ; B = -2.57i + 3.06j

Hence ; A .B

( 2.394 i + 6.57j ) . ( -2.57 + 3.06j ) = 13.95

8 0

3 years ago

What are the philological elements of interior design most like?

sp2606 [1]

Answer:

Ea public address glven via the intercom system of a large buildingxplanation:

7 0

2 years ago

If the specific surface energy for aluminum oxide is 0.90 J/m2 and its modulus of elasticity is (393 GPa), compute the critical

vampirchik [111]

Answer:

critical stress required for the propagation is 27.396615 × $10^{6}$ N/m²

Explanation:

given data

specific surface energy = 0.90 J/m²

modulus of elasticity E = 393 GPa = 393 × $10^{9}$ N/m²

internal crack length = 0.6 mm

to find out

critical stress required for the propagation

solution

we will apply here critical stress formula for propagation of internal crack

( σc ) = $\sqrt{\frac{2E\gamma s}{\pi a}}$ .....................1

here E is modulus of elasticity and γs is specific surface energy and a is half length of crack i.e 0.3 mm = 0.3 × $10^{-3}$ m

so now put value in equation 1 we get

( σc ) = $\sqrt{\frac{2E\gamma s}{\pi a}}$

( σc ) = $\sqrt{\frac{2*393*10^9*0.90}{\pi 0.3*10^{-3}}}$

( σc ) = 27.396615 × $10^{6}$ N/m²

so critical stress required for the propagation is 27.396615 × $10^{6}$ N/m²

6 0

3 years ago

You set a sensor to transmit the wind speed on top of a mountain. Which of these languages are you most likely to have used?

kifflom [539]

The programming language that is most likely used to transmit the wind speed is: B. SQL.

SQL is an acronym for structured query language and it can be defined as a domain-specific programming language that is designed and developed for the management of various data that are saved in a relational or structured database.

This ultimately implies that, a structured query language (SQL) can be used to communicate with a database in accordance with the American National Standards Institute (ANSI) standards.

In conclusion, the programming language that is most likely used to transmit the wind speed is SQL.