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irga5000 [103]
2 years ago
11

A heat engine has a hot reservoir of 490°C and a cold reservoir of 210°C. What is the efficiency of the engine?

Physics
2 answers:
elena-14-01-66 [18.8K]2 years ago
4 0

ec=(TH-TC)/TH

ec=(490-210)/490=57.1%

Nookie1986 [14]2 years ago
3 0
<span>Efficiency is the measure of how efficient a process is. It is used to assess the ability of a process in avoiding waste energy, materials, money and time in doing a desirable output. It is calculated in thermodynamics as:

Efficiency = 1 - Tc / Th

</span>Efficiency = 1 - 210 / 490
Efficiency = 0.57
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Answer:

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Explanation:

As we know that the string is horizontal here

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now we will have

F = qE

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F = 6.57 \times 10^{-2} N

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now we have

6.57 \times 10^{-2} = (6.80 \times 10^3)E

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4 0
3 years ago
A force causes a mass of 4 kg to have an acceleration of 8 m/s2. Suppose something causes the mass to be one-quarter of its orig
solniwko [45]

Explanation:

From Newton's second law:

F = ma

Given that m = 4 kg and a = 8 m/s²:

F = (4 kg) (8 m/s²)

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5 0
3 years ago
A 25 N force stretches a spring 280 cm. What was the spring constant? ​
boyakko [2]

Answer:

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4 0
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dezoksy [38]

Answer:

Energy expenditure in K cals/min = 10 K cals /min (approximately)

Explanation:

As we know

Energy expenditure in Kcal/min=  METs x 3.5 x Body weight (kg) / 200

Given is METs=7.6

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putting the values in formula,

Energy expenditure in K cals/min=  7.6 x 3.5 x 78.02 / 200

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Therefore, Energy expenditure in K cals/min by Jazz will be approximately 10 K cals /min

8 0
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Answer:

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