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

1 answer:

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>

You might be interested in

Helppppppp pleaseeee

SVETLANKA909090 [29]

Answer: (Sorry, but I don't know how to calculate mass)

1. 15 N

2. 0.4921 $\frac{ft}{s^2}$ (feet per second squared)

4. 150 N

5. 8.202 feet per second squared

3 0

2 years ago

How does size of an object affect its gravity

irakobra [83]

Answer:

the more particles packed together the faster it falls

Explanation:

the mass + the 1 constant g-force = the speed without adding air resistance

6 0

3 years ago

Which of the following is not a use of electromagnetic waves? a night-vision bremote controls c x-rays d all are used of electro

sergey [27]

Use of electromagnetic because it moves very faster than others for example xrays theynar very very slow so that not It it is d.

4 0

4 years ago

n oscillator is driven by a sinusoidal force. The frequency of the applied force A : must be less than the natural frequency of

lilavasa [31]

Answer:

B : is independent of the natural frequency of the oscillator

Explanation:

You can apply any force you like to a natural oscillator. It is independent of the natural frequency of the oscillator.

The result you get will depend on how the frequency of the applied force and the natural frequency relate to each other. It will also depend on the robustness of the oscillator with respect to the applied force.

Clearly, if the force is small enough, it will have no effect on the oscillator. If it is large enough, it will overpower any motion the oscillator may attempt. For forces in the intermediate range, there will be some mix of natural oscillation and forced behavior. One may modulate the other, for example.

5 0

3 years ago

Which statement accurately describes what happens when water turns to steam in terms of energy?

Fynjy0 [20]

The correct answer is D. The water absorbs energy which causes the water molecules to have more kinetic and potential energy, changing their configuration from a liquid to a gas.

4 0

3 years ago