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BlackZzzverrR [31]

4 years ago

13

Which of the following has led to a safer and more prosperous global community within the last century? the Bronze Age composite

materials new materials ceramics

2 answers:

sattari [20]4 years ago

4 0

Answer:

The bronze age

musickatia [10]4 years ago

4 0

Answer:

C.

Explanation:

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Is 4/16 equal in measurement to 1/4

Alja [10]

Answer:yes

Explanation:

5 0

3 years ago

Read 2 more answers

Which of the following does a finding of no significant impact (FONSI) negate the need for?

garik1379 [7]

4 environmental accessment

5 0

3 years ago

Rsidential Solar Solution:a. A type of photovoltaic solar panel manufactured in China receives a rating of 250W. The rating proc

aksik [14]

Answer:

a) $\eta = 13.455\%$ , b) $E_{day} = 812.716\,kJ$ , c) $C_{month. total} = 19.505\, USD$ , d) $t = 40.588\,years$

Explanation:

a) The area of the solar panel is:

$A = (20\,ft^{2})\cdot (\frac{0.3048\,m}{1\,ft} )^{2}$

$A = 1.858\,m^{2}$

The energy potential is determined herein:

$\dot E_{o} = (1000\,\frac{W}{m^{2}} )\cdot (1.858\,m^{2})$

$\dot E_{o} = 1858\,W$

The efficiency of the solar panel is:

$\eta = \frac{\dot E}{\dot E_{o}}\times 100\%$

$\eta = \frac{250\,W}{1858\,W}\times 100\%$

$\eta = 13.455\%$

b) The energy generated by the solar panel is presented below:

$E_{day} = (0.135)\cdot (150\,\frac{W}{m^{2}} )\cdot (20\,ft^{2})\cdot \left(\frac{0.3048\,m}{1\,ft} \right)^{2}\cdot (6\,h)\cdot (\frac{3600\,s}{1\,h} )\cdot (\frac{1\,kJ}{1000\,J} )$

$E_{day} = 812.716\,kJ$

c) The energy generated per month and per panel is:

$E_{month} = 30\cdot E_{day}$

$E_{month} = 30 \cdot (812.716\,kJ)\cdot \left(\frac{1\,kWh}{3600\,kJ} \right)$

$E_{month} = 6.773\,kWh$

Monthly energy savings due to the use of 18 panels are:

$C_{month, total} = 18\cdot E_{month}\cdot c$

$C_{month, total} = 18\cdot (6.773\,kWh)\cdot (\frac{0.16\,USD}{1\,kWh} )$

$C_{month. total} = 19.505\, USD$

d) The payback of the solar energy system is:

$t = \frac{9500\,USD}{12\cdot (19.505\,USD)}$

$t = 40.588\,years$

6 0

3 years ago

What is the<br> engineering

Oliga [24]

<em>Engineering</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>profession</em><em> </em><em>which</em><em> </em><em>deals </em><em>with</em><em> </em><em>building</em><em> </em><em>the</em><em> </em><em>structures</em><em> </em><em>like</em><em> </em><em>bridge</em><em>,</em><em>house</em><em>,</em><em>roads</em><em> </em><em>etc</em><em>.</em>

<em>Hope</em><em> </em><em>it</em><em> </em><em>helps</em><em>.</em><em>.</em><em>.</em>

8 0

3 years ago

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Write equations used to calculate the diode reverse saturation current, the voltage at which diode goes into resistive behavior,

laiz [17]

Answer:

Diode equation for reverse saturation current

$I_o = A\times e^{\frac{-Eg}{KT}} + B\times e^{\frac{-Eg}{2KT}}$

Voltage at which diode goes into Resistive region:V=-5 volts

Voltage at which high level injection occurs:Va=0.55 volt

Voltage at which avalanche multiplication occurs:V=5volts

Explanation:

we take here forward and reverse 0.7 volt and -5 volt

As Diode current equation is express as

$I_D = I_o \times (e^{\frac{V_D}{\eta V_T}} -1 )$ ....................1

here $I_D$ is total current through the diode and $I_o$ is reverse saturated current and $V_D$ is voltage drop across diode and $\eta$ is idealized factor and $V_T$ is thermal voltage

so here we know that when Bios is forward than

$V_D$ = $V_T$ .................2

ans Bios is Reverse than

$V_D$ = $V_R$ ..................3

so here

1. diode reverse saturation current is express as

$I_o = A\times e^{\frac{-Eg}{KT}} + B\times e^{\frac{-Eg}{2KT}}$

and

2. Voltage at which diode go into Reverse behavior will be

$V_D$ = $V_R$ = -5 volt

and

3. voltage at which high level injection occur that is

Va = 0.55 volt

and

4. voltage at which avalanche multiplication occurs is

Va = 5 volt

6 0

3 years ago