Answer:
You are a historian who is compiling information on the changing materials used in a product in one of the categories listed below. Choose a product that uses a variety of materials that have been discussed in this lesson (for example, a car or a tennis racket). Using online or library resources, research past materials used to create the product. Be sure to discuss the materials currently being used for the design and include information on the sustainability of these resources. Your research must also explain why the materials changes were made (for example, safety, cost, or weight). Keep track of your references so that you can document all of the resources used for your report.
Answer:
Given:
P₁ = 500 kPa
T₁ = 860 K
P₂= 100 kPa
T₂ = 460 K
Let's take entropy properties of T1 and T2 from ideal properties of air,
at T = 860K, s(T₁) = 2.79783 kJ/kg.K
at T = 460K, s(T₂) = 2.13407 kJ/kg.K
using entropy balance equation:
![\frac{\sigma _cv}{m} = s(T_2)- s(T_1) - R In [\frac{P_2}{P_1}]](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5Csigma%20_cv%7D%7Bm%7D%20%3D%20s%28T_2%29-%20s%28T_1%29%20-%20R%20In%20%5B%5Cfrac%7BP_2%7D%7BP_1%7D%5D%20)
= - 0.2018 kJ/kg. K
In this case the entropy is negative, which means the value of exit temperature is not correct, beacause entropy should always be positive(>0).
The answer is False!
The answer is false
Answer:
Keep a gallon of water in your car.
Explanation:
Because.
Answer:
The line voltage of the three phase network is 346.41 V
Explanation:
Star Connected Load
Resistance, R₁ = R₂ = R₃ = 18 Ω
For a star connected load, the line current = the phase current, that is we have

Whereby the the voltage across each resistance =
is given by the relation;
=
× R
Hence;
=
=
× R = 25 × 8 = 200 V
Therefore we have;
The line voltage,
= √3 ×
= √3 × 200 = 346.41 V.
Hence, the line voltage of the three phase network = 346.41 V.