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3 years ago

Why the efficiency of carnot engine is not 100%

1 answer:

3 0

Well, actually a heat engine using the Carnot cycle whose cold reservoir is maintained at 0 K could in principle be 100% efficient, even if the hot reservoir was merely at the ambient temperature. Since it costs no energy at all to maintain a heat reservoir at the ambient temperature as long as you have a perfect thermal connection to a large thermal capacitor like your swimming pool or a nearby aquifer you’d have built a perpetual motion machine.

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0.0135 kg of steam at 100°C is

lora16 [44]

Answer:

33333.35 kg

Explanation:

I got it right on Acellus, rounded to 33300 sigfigs

8 0

3 years ago

A woman is riding a bicycle at 18.0 m/s along a straight road that runs parallel to and right next to some railroad tracks. She

mr_godi [17]

Answer:

(a) Speed of train is 7.66 m/s and it is traveling away from the bicycle.

(b) Frequency heard by the stationary observer is 821.50 Hz.

Explanation:

Doppler effect is defines as the change in the frequency of the wave as the observer and/or source are moving away or towards each other.

(a) According to the problem,

Speed of the observer, v₀ = 18 m/s

Speed of sound in air, v = 340 m/s

Original frequency emitted by train, f = 840 Hz

Apparent frequency heard by the observer, f₀ = 778 Hz

Let v₁ be the speed of the train.

Since, apparent frequency is less than original frequency i.e. f₀ > f . Hence, train are travelling away from the bicycle.

Thus, the Doppler effect equation is :

$f_{0} = (\frac{v - v_{0} }{v+v_{1} } )f$

Substitute the suitable values in the above equation.

$778 = (\frac{340 -18 }{340+v_{1} } )840$

340 + v₁ = 347.66

v₁ = 7.66 m/s

(b) In this case, speed of observer, v₀ = 0 m/s

Apparent frequency, $f_{0} = (\frac{v }{v+v_{1} } )f$

Substitute the suitable values in the above equation.

$f_{0} = (\frac{340 }{340+7.66 } )840$

f₀ = 821.50 Hz

8 0

4 years ago

How long does it take light to travel 850 km in a vacuum? Answer in ms.(Express your answer to two significant figures.)

poizon [28]

Answer:

0.002833 sec

Explanation:

Speed of light in vacuum is $3\times 10^{8}m/sec$

Given distance = 850 km = 850×1000=850000 m

We have to calculate the time that light take to travel the distance 850 km

Time $T=\frac{distance }{speed}=\frac{850000}{3\times 10^8}=2.833\times 10^{-3}sec$

So the time taken by light to travel 850 km is 0.002833 sec

5 0

3 years ago

Is it true that theodor Schwann used only his own research to develop the cell theory?

slamgirl [31]

No, there were other scientists who developed the cell theory with him.

8 0

4 years ago

Sam and George are riding in separate cars on the freeway. The lanes they are driving in are adjacent. We choose our coordinate

butalik [34]

Answer:

(a) Relative speed of Sam = -7 mph

(b) Relative speed of George = 7 mph

Explanation:

We have given speed of Sam 65 mph in north direction.

And speed of George is 72 mph also in north direction

We have find the relative velocity of both Sam and George

(a) Speed of Sam relative to George = speed of Sam - speed of George = 65 -72 = -7 mph

(b) Speed of George with respect to Sam = speed of George - speed of Sam = 72-65 = 7 mph

3 0

3 years ago