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1 year ago

If steam enters a turbine at 600K and is exhausted at 400K, calculate the efficiency of the engine.

2 answers:

8 0

The formular for efficiency = change in temprature/ initial temprature
change in temprature = 600 - 400 = 200
efficiency = 200/600 = 0.333 = 33.3%'

ikadub [295]1 year ago

3 0

The correct answer to the question is 33.3 % i.e the efficiency of the engine is 33.3 %.

CALCULATION:

The steam enters a turbine at 600 K.

Hence, the temperature of the source T = 600 K.

The steam is exhausted at a temperature 400 K.

Hence, the temperature of the sink T' = 400 K

We are asked to calculate the efficiency of the engine.

The efficiency of a heat engine whose source is at temperature T K and sink at T' is calculated as -

efficiency $\eta\ =\ 1-\frac{T'}{T}$

$=\ 1-\frac{400\ K}{600\ K}$

$=\ 1-\frac{2}{3}$

$=\ \frac{1}{3}$

$=\ 33.3\%$ [ans]

Hence, the efficiency of the engine is 33.3 %.

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The 1.5-in.-diameter shaft AB is made of a grade of steel with a 42-ksi tensile yield stress. Using the maximum-shearing-stress

PolarNik [594]

Answer:

T = 0.03 Nm.

Explanation:

d = 1.5 in = 0.04 m

r = d/2 = 0.02 m

P = 56 kips = 56 x 6.89 = 386.11 MPa

σ = 42-ksi = 42 x 6.89 = 289.58 MPa

Torque = T =?

<u>Solution:</u>

σ = (P x r) / T

T = (P x r) / σ

T = (386.11 x 0.02) / 289.58

T = 0.03 Nm.

7 0

2 years ago

You hang different masses M from the lower end of a vertical spring and measure the period T for each value of M. You use Excel

Svetradugi [14.3K]

Answer:

a)693.821N/m

b)17.5g

Explanation:

We the Period T we can find the constant k,

That is

$T = 2 \pi \sqrt{\frac{m}{k}}$

squaring on both sides,

$T^2=\frac{4\pi^2}{k}M +\frac{4\pi^2}{k}m_{spring}$

where,

M=hanging mass, m = spring mass,

k =spring constant

T =time period

a) So for the equation we can compare, that is,

$y=T^2=0.0569x+0.0010$

the hanging mass M is x here, so comparing the equation we know that

$\frac{4\pi^2}{k}=0.0569\\k= \frac{4\pi^2}{0.0569}\\k=693.821N/m$

b) In order to find the mass of the spring we make similar process, so comparing,

$\frac{4\pi^2}{k}m =0.001\\m=\frac{0.004k}{4\pi^2} =\frac{0.001*693.821}{4\pi^2}\\m=0.0175kg\\m=17.5g$

3 0

2 years ago

An object of mass 24kg is accelerated up a frictionless place incline at an angle of 37° with horizontal by a constant force, st

RoseWind [281]

a) Average power: 1425 W

b) Instantaneous power at 3.0 sec: 2850 W

Explanation:

The motion of the object along the ramp is a uniformly accelerated motion (because the force applied is constant), so we can use the suvat equation

$s=ut+\frac{1}{2}at^2$

where

s = 18 m is the displacement along the ramp

u = 0 is the initial velocity

t = 3.0 s is the time taken

a is the acceleration of the object along the ramp

Solving for a,

$a=\frac{2s}{t^2}=\frac{2(18)}{(3.0)^2}=4 m/s^2$

Now we can apply Newton's second law to find the net force on the object:

$F=ma=(24 kg)(4 m/s^2)=96 N$

This net force is the resultant of the applied force forward ( $F_a$ ) and the component of the weight acting backward ( $mg sin \theta$ ), so we can find what is the applied force:

$F=F_a - mg sin \theta\\F_a = F+mg sin \theta = 96+(24)(9.8)(sin 37^{\circ})=237.5 N$

where

m = 24 kg is the mass of the object

$g=9.8 m/s^2$ is the acceleration of gravity

Now we can finally find what is the work done by the applied force, which is parallel to the ramp, therefore:

$W=F_a s = (237.6)(18)=4276 J$

where s = 18 m is the displacement.

Therefore the average power needed is:

$P=\frac{W}{t}=\frac{4276}{3}=1425 W$

The instantaneous power at any point of the motion is given by

$P=F_av$

where

$F_a$ is the force applied

v is the velocity of the object

We already calculated the applied force:

$F_a=237.5 N$

While since this is a uniformly accelerated motion, we can find the velocity at the end of the 3.0 seconds using the suvat equation:

$v=u+at=0+(4)(3.0)=12.0 m/s$

And therefore, the instantaeous power at 3.0 sec is:

$P=Fv=(237.5)(12)=2850 W$

Learn more about power:

brainly.com/question/7956557

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8 0

1 year ago

Jin walked 4 km on a straight path to get to the sandwich shop. He traveled 30° south of east.

Molodets [167]

Answer: -2 km

Explanation:

If we imagine Jin's movement to be the hypothenuse of a right triangle, then the southern component of Jin's movement corresponds to the side of the triangle opposite to the angle of 30 degrees. Therefore, the magnitude of this southern component is given by

However, the angle of 30 degrees is south of east: this means that the direction of this southern component is south, and since we generally take north as positive direction, we must add a negative sign, so the correct answer is

-2 km

3 0

2 years ago

Read 2 more answers

If you're ever standing on a mountaintop when a dark cloud passes overhead and your hair stands up, get off the mountain fast. H

OleMash [197]

Answer:

The hairs would have acquired charge by the passing of dry winds resulting in the loss of electron.

Explanation:

While standing on the top of a mountain if a person gets its hairs stand up after a cloud passes over, this might happen due to the static electric charges on the lower surface of the cloud are opposite in nature to that of hairs which the hairs would have acquired by the passing of dry winds which would have resulted in the loss of electron from the hair tip.

Similar case happens when we rub a dry plastic ruler or a dry plastic comb on our hairs.

8 0

2 years ago