A 2-meter high wave with a wavelength of 100 meters and period of 20 seconds would be moving how fast?

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

777dan777 [17]

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:

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7 0

3 years ago

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An automobile engine takes in 4000 j of heat and performs 1100 j of mechanical work in each cycle. (a) calculate the engine's ef

Semmy [17]

(a) The efficiency of an engine is defined as the ratio between the work done by the engine and the heat it takes in:
$\eta= \frac{W}{Q_{in}}$
The engine in this problem does a work of $W=1100 J$ and it takes in $Q_{in}=4000 J$ of heat, therefore its efficiency is
$\eta= \frac{1100 J}{4000 J}=0.275 = 27.5 \%$

(b) The heat taken by the machine is 4000 J; of this amount of heat, only 1100 J are converted into useful work. This means that the rest of the heat is wasted. Therefore, the wasted heat is the difference between the heat in input and the work done by the engine:
$Q_{wasted}=Q_{in}-W=4000 J-1100 J=2900 J$

7 0

3 years ago

The temperature of a smelting furnace is found to be 2000 ℃. Find the

IRISSAK [1]

Answer:

a) The equivalent temperature of 2000 ºC is 3632 ºF.

b) The equivalent temperature of 2000 ºC is 4091.67 R.

c) The equivalent temperature of 2000 ºC is 2273.15 K.

d) The equivalent temperature of 2000 ºC is 1600 ºRe.

Explanation:

a) The equivalent temperature on the Fahrenheit scale is defined by the following formula:

$T_{F} = \frac{9}{5}\cdot T_{C}+32$ (Eq. 1)

Where:

$T_{C}$ - Temperature, measured in degrees Celsius.

$T_{F}$ - Temperature, measured in degrees Fahrenheit.

If we know that $T_{C} = 2000\,^{\circ}C$ , then the temperature is:

$T_{F} = \frac{9}{5}\cdot (2000\,^{\circ}C)+32\,^{\circ}F$

$T_{F} = 3632\,^{\circ}F$

The equivalent temperature of 2000 ºC is 3632 ºF.

b) From result in a) we determine the equivalent temperature on the Rankine scale by using the following formula:

$T_{R} = T_{F}+459.67$ (Eq. 2)

Where:

$T_{F}$ - Temperature, measured in degrees Fahrenheit.

$T_{R}$ - Temperature, measured in Rankine.

If we know that $T_{F} = 3632\,^{\circ}F$ , then the temperature is:

$T_{R} = 3632\,^{\circ}F+459.67\,R$

$T_{R} = 4091.67\,R$

The equivalent temperature of 2000 ºC is 4091.67 R.

c) The equivalent temperature on the absolute scale is calculated by using this expression:

$T_{K} = T_{C}+273.15$ (Eq. 3)

Where:

$T_{C}$ - Temperature, measured in degrees Celsius.

$T_{K}$ - Temperature, measured in Kelvin.

If we know that $T_{C} = 2000\,^{\circ}C$ , then the temperature is:

$T_{K} = 2000\,^{\circ}C+273.15\,K$

$T_{K} = 2273.15\,K$

The equivalent temperature of 2000 ºC is 2273.15 K.

d) The equivalent temperature on the Réaumur scale is calculated by applying this expression:

$T_{Re} = \frac{4}{5}\cdot T_{C}$ (Eq. 4)

Where:

$T_{C}$ - Temperature, measured in degrees Celsius.

$T_{Re}$ - Temperature, measured in degrees Réaumur.

If we know that $T_{C} = 2000\,^{\circ}C$ , then the temperature is:

$T_{Re} = \frac{4}{5}\cdot (2000\,^{\circ}C)$

$T_{Re} = 1600\,^{\circ}Re$

The equivalent temperature of 2000 ºC is 1600 ºRe.

5 0

3 years ago

15 pointsss please help meeeeeeeeeee

AveGali [126]

A. Acceleration! ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ

5 0

3 years ago

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a car accelerates at a constant rate from 15 m/s to 25 m/s while it travels a distance of 125 m. How long does it take to achiev

atroni [7]

T=Vf-Vi/s
25m/s -15m/s/ 125m
10m/s /125m
=0.08s
I hope it’s correct !

6 0

3 years ago