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bekas [8.4K]
3 years ago
11

What is the efficiency of a device that takes in 400 J of heat and does 120 J

Physics
2 answers:
777dan777 [17]3 years ago
7 0

The efficiency of the device is 30 %

Explanation:

The efficiency of a heat engine is given by:

\eta = \frac{W}{Q_{in}}

where

W is the work done by the engine

Q_{in} is the heat in input to the engine

For the device in this problem, we have:

W = 120 J is the work done

Q_{in} = 400 J is the heat in input

Substituting, we find the efficiency:

\eta=\frac{120}{400}=0.30

which corresponds to an efficiency of 30%.

Learn more about work:

brainly.com/question/6763771

brainly.com/question/6443626

#LearnwithBrainly

Alinara [238K]3 years ago
4 0

Answer: 30%

Explanation:

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Answer:

W =1562.53 N

Explanation:

It is given that,

Radius of the aluminium ball, r = 24 cm = 0.24 m

The density of Aluminium, d=2698.4\ kg/m^3

We need to find the thrust and the force. The mass of the liquid displaced is given by :

m=dV

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Weight of the displaced liquid

W = mg

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So,

W=dg\times \dfrac{4}{3}\pi r^3\\\\W=2698.4\times 10\times \dfrac{4}{3}\times \pi \times (0.24)^3\\\\W=1562.53\ N

So, the thrust and the force is 1562.53 N.

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2 years ago
an aeroplane moving horizontally with a speed of 180 km/hr drops a food packet while flying at a height of 490m . the horizontal
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The time the package travels horizontally is equal to the time it takes to hit the ground. This can be calculated using:
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5 0
2 years ago
The diver uses compressed air to breathe under water. 1700 litres of air from the atmosphere is compressed into a 12-litre gas c
ivann1987 [24]

Answer:

The answer is below

Explanation:

A diver works in the sea on a day when the atmospheric pressure is 101 kPa. The diver uses compressed air to breathe under water. 1700 litres of air from the atmosphere is compressed into a 12-litre gas cylinder. The compressed air quickly cools to its original temperature. Calculate the pressure of the air in the cylinder.

Solution:

Boyles law states that the volume of a given gas is inversely proportional to the pressure exerted by the gas, provided that the temperature is constant.

That is:

P ∝ 1/V;   PV = constant

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P₁V₁ = P₂V₂

100 kPa * 1700 L = P₂ * 12 L

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2 years ago
A metal pot is filled with water and placed on top of a stove. As the stove heats up, the water begins to boil, and steam can be
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This type of system is an example of open system because the vapors leave the system and goes into the atmosphere.

<h3>What is open system?</h3>

An open system is a type of system that has external interactions which means energy, or material transfers into or out of the system.

So we can conclude that this type of system is an example of open system because the vapors leave the system and goes into the atmosphere.

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4 0
1 year ago
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Answer:

<h3>Motion which repeats itself after regular intervals of time is known as periodic motion.</h3>
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