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brilliants [131]

3 years ago

10

What is the thermal energy contained within a cubic kilometre of granite (in barrels of oil equivalent) for every one degree cha

nge in temperature? Use the following parameters in your calculation: Specific heat of granite = 790 (J/kgC) Density of granite = 2700 kg/m3 Energy in 1 barrel of oil = 6.118e9 J

1 answer:

AnnZ [28]3 years ago

4 0

Answer:

348643.34 barrels of oil

Explanation:

Given;

Volume of the granite = 1 km³ = 1000³ m³

Specific heat of granite, C = 790 J/kg.°C

Density of granite = 2700 kg/m³

Energy in 1 barrel of oil = 6.118 × 10⁹ J

For every 1° change in temperature, ΔT = 1°C

Now,

The thermal energy stored is given as;

Thermal energy = mCΔT

where, m is the mass

the mass of 1 km³ of granite = Density × Volume

or

the mass of 1 km³ of granite = 2700 × 1000³ = 27 × 10¹¹ Kg

therefore,

Thermal energy = 27 × 10¹¹ × 790 × 1

or

Thermal energy = 21330 × 10¹¹ J

hence,

the thermal energy in terms of barrels of oil

= Total thermal energy / Energy stored in 1 barrel of oil

= 21330 × 10¹¹ J / ( 6.118 × 10⁹ J per barrel )

= 348643.34 barrels of oil

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The costs of mining and transporting coal are roughly independent of the heating value of the coal. Consider:

Paul [167]

Answer:

2

Explanation:

5 0

3 years ago

Two balanced Y-connected loads in parallel, one drawing 15kW at 0.6 power factor lagging and the other drawing 10kVA at 0.8 powe

NemiM [27]

Answer:

(a) attached below

(b) $pf_{C}=0.85$ $lagging$

(c) $I_{C} =32.37 A$

(d) $X_{C} =49.37$ Ω

(e) $I_{cap} =9.72 A$ and $I_{line} =27.66 A$

Explanation:

Given data:

$P_{1}=15 kW$

$S_{2} =10 kVA$

$pf_{1} =0.6$ $lagging$

$pf_{2}=0.8$ $leading$

$V=480$ $Volts$

(a) Draw the power triangle for each load and for the combined load.

$\alpha_{1}=cos^{-1} (0.6)=53.13$ °

$\alpha_{2}=cos^{-1} (0.8)=36.86$ °

$S_{1}=P_{1} /pf_{1} =15/0.6=25 kVA$

$Q_{1}=P_{1} tan(\alpha_{1} )=15*tan(53.13)=19.99$ ≅ $20kVAR$

$P_{2} =S_{2}*pf_{2} =10*0.8=8 kW$

$Q_{2} =P_{2} tan(\alpha_{2} )=8*tan(-36.86)=-5.99$ ≅ $-6 kVAR$

The negative sign means that the load 2 is providing reactive power rather than consuming

Then the combined load will be

$P_{c} =P_{1} +P_{2} =15+8=23 kW$

$Q_{c} =Q_{1} +Q_{2} =20-6=14 kVAR$

(b) Determine the power factor of the combined load and state whether lagging or leading.

$S_{c} =P_{c} +jQ_{c} =23+14j$

or in the polar form

$S_{c} =26.92$ °

$pf_{C}=cos(31.32) =0.85$ $lagging$

The relationship between Apparent power S and Current I is

$S=VI^{*}$

Since there is conjugate of current I therefore, the angle will become negative and hence power factor will be lagging.

(c) Determine the magnitude of the line current from the source.

Current of the combined load can be found by

$I_{C} =S_{C}/\sqrt{3}*V$

$I_{C} =26.92*10^3/\sqrt{3}*480=32.37 A$

(d) Δ-connected capacitors are now installed in parallel with the combined load. What value of capacitive reactance is needed in each leg of the A to make the source power factor unity?Give your answer in Ω

$Q_{C} =3*V^2/X_{C}$

$X_{C} =3*V^2/Q_{C}$

$X_{C} =3*(480)^2/14*10^3$ Ω

(e) Compute the magnitude of the current in each capacitor and the line current from the source.

Current flowing in the capacitor is

$I_{cap} =V/X_{C} =480/49.37=9.72 A$

Line current flowing from the source is

$I_{line} =P_{C} /3*V=23*10^3/3*480=27.66 A$

8 0

3 years ago

NEED HELPASAP what is the moisture content of a board if a test sample that originally weighed 11. 5 oz was found to weigh 10 oz

Viefleur [7K]

Answer:

11.5-10/10= 0.15x100 =15%

Explanation:

3 0

2 years ago

What is closest in meaning to a guild?<br> O rally<br> O framework<br> union<br> O embargo

Degger [83]

Answer:

Union

Explanation:

The correct option is - union

Reason -

Guild is an association of people for mutual aid or the pursuit of a common goal.

Rally is come together in order to provide some support or make a shared effort.

Framework is a basic structure underlying a system, concept, or text.

Union is a club, society, or association formed by people with a common interest or purpose.

An embargo is a government order that restricts commerce with a specified country or the exchange of specific goods.

5 0

2 years ago

List all information for each order item. Include an item total, which can be calculated by multiplying the Quantity and Paid ea

Zigmanuir [339]

Answer:

#include<iostream>

Using namespace std;

int main()

{

int n, qty;

double price, amount;

cout<<"Number of items ";

cin>>n;

cout<<"ITEM<<"\t"<<"QUANTITY"<<"\t"<<"PRICE"<<"\t"<<"ITEM TOTAL";

for(int i= 1; I<= n; i++)

{

cin>>qty;

cin>>price;

amount = qty * price;

cout<<i<<"\t "<<qty<<"\t"<<price<<"\t"<<amount;

}

}

Explanation

The above program is written in C++ programming language

5 variables are declared and used in the program

n is declared as an integer to represent the total number of items

qty is declared as integer to represent the total quantity of each item

price is declared as double to represent the amount of each individual item

amount is declared as double to represent the total amount of an item; it is gotten by qty * price

i is declared as integer to iterated between each items

The amount of each item is calculated within the iteration and also printed immediately

3 0

3 years ago