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Mila [183]
3 years ago
7

A heat engine operating between energy reservoirs at 20?c and 600?c has 30% of the maximum possible efficiency.

Physics
1 answer:
Anarel [89]3 years ago
8 0
 <span>The maximum possible efficiency, i.e the efficiency of a Carnot engine , is give by the ratio of the absolute temperatures of hot and cold reservoir. 
η_max = 1 - (T_c/T_h) 

For this engine: 
η_max = 1 - [ (20 +273)K/(600 + 273)K ] = 0.66 = 66% 

The actual efficiency of the engine is 30%, i.e. 
η = 0.3 ∙ 0.664 = 0.20 = 20 % 

On the other hand thermal efficiency is defined as the ratio of work done to the amount of heat absorbed from hot reservoir: 
η = W/Q_h 

So the heat required from hot reservoir is: 
Q_h = W/η = 1000J / 0.20 = 5000J</span>
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<h2>emf = 9.3 x 10³</h2>

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l = 2.30 x 10⁴ m  and v = 7.5 x 10³

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Lelu [443]
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Question 8 (1 point)
sineoko [7]

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6 0
3 years ago
a car with a mass of 1200 kilograms is moving around a circular curve at a uniform velocity of 20 meters per second. the centrip
qaws [65]
Well, first of all, a car moving around a circular curve is not moving
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The centripetal force that keeps an object moving in a circle is

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We want to know the radius, to rearrange the formula to give us
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                                          F     =  m s² / r

Multiply each side by 'r':       F· r  =  m · s²

Divide each side by 'F':            r  =  m · s² / F    

We know all the numbers on the right side,
so we can pluggum in:

                      r  =       m       ·        s²      /     F

                      r  =  (1200 kg) · (20 m/s)² / (6000 N) .

I'm pretty sure you can finish it up from here.

                                      


5 0
3 years ago
A flywheel with radius of 0.300 m starts from rest and accelerates with a constant angular acceleration of 0.400 rad/s2.For a po
oksian1 [2.3K]

Answer:

0.12\ m/s^2

Explanation:

Given that,

The radius of a flywheel, r = 0.3 m

Angular acceleration of a flywheel, \alpha =0.4\ rad/s^2

We need to find the magnitude of the tangential acceleration after 2.00 s of acceleration.

The relation between the tangential and angular acceleration is given by :

a_t=r\alpha \\\\a_t=0.3\times 0.4\\\\a_t=0.12\ m/s^2

So, the required magnitude of tangential acceleration is 0.12\ m/s^2.

6 0
3 years ago
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