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2 years ago

A dice is thrown 420 times and the number 6 is obtained 63 times; express the frequency of obtaining

Engineering

1 answer:

STatiana [176]2 years ago

6 0

Answer: 15%

Explanation:

Frequency of obtaining = 63/420 = 0.15 = 15%

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A well-established way of power generation involves the utilization of geothermal energy-the energy of hot water that exists nat

jeka94

Answer:

the maximum thermal efficiency is 29%

Explanation:

the maximum efficiency for a thermal engine that works between a cold source and a hot source is the one of a Carnot engine. Its efficiency is given by

Maximum efficiency= 1 - T2/T1

where

T2= absolute temperature of the cold sink (environment)= 20°C + 273 = 293

T2= absolute temperature of the hot source (hot water supply) = 140°C + 273 = 413

therefore

Maximum efficiency= 1 - T2/T1 = 1 - 293/413 = 0,29 =29%

3 0

3 years ago

Tamara has received multiple bids from general contractors to install a new pool in her backyard. How should she go about select

vovikov84 [41]

Answer:

Option C

Explanation:

Tamara must choose the contractor who can provide best services among all and also has a fair pricing. Hence, option 3 is correct

If she chooses the contractor with low price, there are chances that the quality will not be good. Hence, option 2 is incorrect

Option 4 is incorrect because the contractor must take inputs of the contracting person or agency.

Option 1 is incorrect because selecting some one on the basis of reviews can be a biased selection of contractor.

7 0

3 years ago

Consider a Carnot heat-engine cycle executed in a closed system using 0.028 kg of steam as the working fluid. It is known that t

Paha777 [63]

Answer:

T=138 °C

Explanation:

Given that

m = 0.028 kg

Net work output W= 60 KJ

T₂=2T₁

As we know that efficiency of Carnot heat engine given as

$\eta=1-\dfrac{T_1}{T_2}$

$\eta=1-\dfrac{T_1}{2T_1}$

η = 0.5

We know that

$\eta=\dfrac{W}{Q_a}$

Qa=heat addition

W= net work output

$\eta=\dfrac{W}{Q_a}$

$0.5=\dfrac{60}{Q_a}$

Qa= 120 KJ

From first law

Qa= W+ Qr

Qr= 120 - 60

Qr= 60 KJ

Qr Is the heat rejection.

Heat rejection per unit mass

Qr=60 / 0.028 = 2142.85 KJ/kg

Qr= 2142.85 KJ/kg

Temperature at which latent heat of steam is 2142.85 KJ/kg will be our answer.

T=138 °C

The temperature corresponding to 2142.85 KJ/kg will be 138 °C.

T=138 °C

8 0

3 years ago

Plateau Creek carries 5.0 m^3 /s of water with a selenium (Se) concentration of 0.0015 mg/L. A farmer withdraws water at a certa

Bond [772]

Answer:

The correct answer is "4.8137 m³". The further explanation is given below.

Explanation:

Firstly we have to calculate the concentration of Se:

$C = 0.0015 \ mg/L\times \frac{1g}{1000 mg}\times \frac{1 \ mol}{79 \ g}$

$=1.9\times 10^{-8} \ mol/L$

Concentration the fish can take:

$=0.04 \ mg/L\times \frac{1 \ g}{1000mg}\times \frac{1 \ mol}{79 \ g}$

According to the general dilution principle will be:

⇒ $M_1V_1 = M_2V_2$

The volume that can take the farmer will be:

$V_2 = 1.9\times 10^{-8} M\times \frac{5\times 10^3 \ L}{5.1\times 10-7 M}$

$=186.27 \ L$

On converting this into m³, we get

= $0.18627 \ m^3$

Finally the volume the farmer can remove would be:

$V = 5-0.18627$

$= 4.8137 \ m^3$

7 0

3 years ago

Select the correct answer. Jude is a mechanical engineer. He works in the automobile industry. He is creating a prototype of an

Nikolay [14]

Answer:

Bid bureau of investigation

6 0

3 years ago