Answer:
The expression for the concentration of electrons is P = NA - ND
Explanation:
Please look at the solution in the attached Word file
Answer:
And Im still going with B..
Answer:
<em>hello your question is incomplete attached below is the missing diagram </em>
answer : 7.87 KN
Explanation:
The magnitude of the resultant force = 7.87 KN
from fig 1
First step :
calculate the resultant force along the x- direction
Frx = ∑Fx = +8 kN - Fcos45° - 14cos 30°
= -4.1243 - 0.7071 F
next :
calculate the resultant force along the y- direction
Fry = ∑Fy = -Fsin45° + 14sin30°
= -0.7071 F + 7
attached below is the remaining part of the detailed solution
Answer:
a) the actual thermal efficiency is 15.17%
b) the maximum thermal efficiency is 29.55%
Explanation:
a) the actual thermal efficiency is for a heat engine is,
E actual = Power obtained / Necessary heat rate as input = P/q
q = F * c * (Tinitial - Tfinal) , F = mass flow rate , c=specific heat of water ( we assume c= 1 cal/gr°C = 4.186 J/gr°C= 4.186 kJ/kg°C)
q = 210 Kg/s * 4.186 kJ/kg°C (150°C - 90 °C) = 52743.6 kW
therefore
E actual = 8000 kW /52743.6 kW = 0.1517 = 15.17%
b) the maximum thermal efficiency for the same heat source and heat sink corresponds to the one of a Carnot engine. Where,
E max = 1 - Tc/Th , Th is the absolute temperature of the hot heat source and Tc is the absolute temperature of the cold heat sink.
therefore
Th= 150°C + 273 °C = 423 K
Tc= 25°C + 273°C = 298 K
thus
E max = 1- 298/423 = 0.2955 = 29.55%
Answer:
Accuracy and precision allow us to know how much we can rely on a measuring device readings. ±.001 as a "accuracy" claim is vague because there is no unit next to the figure and the claim fits better to the definition of precision.
Explanation:
Accuracy and Precision: the golden couple.
Accuracy and precision are key elements to define if a measuring device is reliable or not for a specific task. Accuracy determines how close are the readings from the ideal/calculated values. On the other hand, precision refers to repeatability, that is to say how constant the readings of a device are when measuring the same element at different times. One of those two key concepts may not fulfill the criteria for measuring tool to be used on certain engineering projects where lack of accuracy (disntant values from real ones) or precision (not constant readings) may lead to malfunctons and severe delays on the project development.
±.001 what unit?
The manufacturer says that is an accuracy indicator, nevertheless there is now unit stated so this is not useful to see how accurate the device is. Additionally, That notation is more used to refer to device tolerances, that is to say the range of possible values the instrument may show when reading and element. It means it tells us more about the device precision during measurments than actual accuracy. I would recommend the following to the dial calipers manufacturers to better explain its measurement specifications:
- Use ±.001 as a reference for precision. It is important to add the respective unit for that figure.
- Condcut test to define the actual accuracy value an present it using one of the common used units for that: Error percentage or ppm.