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3 years ago

14

A heat engine cycle is executed with steam in the saturation dome. The pressure of steam is 1.1 MPa during heat addition and 0.3

MPa during heat rejection. The highest possible efficiency of this heat engine is:

1 answer:

klio [65]3 years ago

8 0

Answer:The highest possible efficiency of this heat engine is 11%

Explanation:

Saturated water temperature at P1, Pressure in Heat addition,

1.1 MPa=185°C +273= 458K

Saturated water temperature at P2, Pressure in Heat rejection,

0.3MPa=133.5°C+ 273=406.5K

The highest possible efficiency of any heat engine is the Carnot efficiency given as

Carnot efficiency, ηmax = 1- (T2/ T1)

1- (406.5K/458K)

1-0.88755=0.112

=11%

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Answer:

v (speed) = S / t = 4 * 400 m / (6 * 60 sec) = 4.4 m/s

The average velocity is zero because there is no net vector displacement.

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3 years ago

A physics student stands on a cliff overlooking a lake and decides to throw a softball to her friends in the water below. She th

Andre45 [30]

The horizontal distance covered by the ball before hitting the water is 70.4 m

Explanation:

The motion of the ball is the motion of a projectile, so it consists of two independent motions:

A uniform motion along the horizontal (x) direction
A uniformly accelerated motion along the vertical (y) direction

We start by calculating the time of flight of the ball. This can be done by analyzing the vertical motion. We can use the following suvat equation:

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

where:

s = -16.5 m is the vertical displacement of the ball (it is negative because we take upward as positive direction)

$u_y$ is the initial vertical velocity of the ball, which is given by

$u_y = u sin \theta$

where

u = 23.5 m/s is the initial velocity

$\theta=33.5^{\circ}$ is the angle of projection

Substituting,

$u_y=(23.5)(sin 33.5^{\circ})=13.0 m/s$

$a=g=-9.8 m/s^2$ is the acceleration of gravity, downward

Substituting everything into the equation we get:

$-16.5=13.0t-4.9t^2\\4.9t^2-13.0t-16.5=0$

Solving the equation for t, we find the time of flight of the ball:

t = -0.94 s

t = 3.59 s

We ignore the 1st solution since it is negative, so the ball reaches the water after 3.59 seconds.

Now we analyze the horizontal motion of the ball. The horizontal velocity is constant and it is:

$v_x=u cos \theta=(23.5)(cos 33.5^{\circ})=19.6 m/s$

Therefore, the horizontal distance covered in a time t is

$d=v_x t$

And substituting t = 3.59 s, we find

$d=(19.6)(3.59)=70.4 m$

So, the horizontal distance covered by the ball before hitting the water is 70.4 m.

Learn more about projectile motion:

brainly.com/question/8751410

#LearnwithBrainly

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4 years ago

In a home's central heating system, when the room temperature measured by the thermostat reaches a set value, the thermostat sen

shutvik [7]

These actions are an example of feedback.
Given that the room has reached the desired temperature, there is no more need for it to be heated, at least until the temperature drops a bit. This is why the thermostat sends feedback about this situation to the heater, which immediately switches off until it is needed again.

3 0

3 years ago

Read 2 more answers

The spectral distribution of the radiation emitted by a diffuse surface may be approximated as follows. HW 2 Q2 (a) What is the

Ronch [10]

Answer:

a)<em> 2000 W/m² </em><em>; </em>b) 636.94 W/m<em>².sr ; </em><em>c) </em>0.5

Explanation:

a)

The formula for calculation of total emissive power is:

Total emissive power = E = $\int\limits^\alpha_0$ E'<em>λdλ</em>

<em> </em>= $\int\limits^a_0$ (0)d<em>λ + </em> $\int\limits^b_a$ (100)d<em>λ + </em> $\int\limits^c_b$ (200)d<em>λ + </em> $\int\limits^d_c$ (100)d<em>λ </em> $\int\limits^e_d$ (0)d<em>λ</em>

<em>where a = 5; b = 10; c = 15; d = 20; e = 25</em>

<em> = 0 +100(10-5) + 200(15-10) +100(20-15) + 0</em>

<em> = 2000 W/m²</em>

b)

The formula for total intensity of radiation is:

I $_{e}$ = E/π = 200/3.14 = 636.94 W/m<em>².sr </em>

<em>c)</em>

Fo submissive power leaving the surface in range π/4 ≤θ≤π/2

[E(π/4 ≤θ≤π/2)]/E = $\int\limits^f_0$ $\int\limits^g_0$ $\int\limits^i_h$ Icosθsinθ dθdΦdλ

where f = infinity, g=2π, h=π/4, i=π/2

By simplifying, we get

= (-1/2)[cos(2π/2)-cos(2π/2)]

= -0.5(-1-0)

=0.5

8 0

3 years ago

9. A soft drink distibutor drove west 11 km from Minnehaha to Nut Plains. She then turned around and drove back east for 209 km

guajiro [1.7K]

Answer:

220km

Explanation:

Given parameters:

Distance traveled from Minnehaha to Nut Plains = 11km

Distance traveled to Dover = 209km

Unknown:

The distance the soft drink distributor traveled = ?

Solution:

To solve this problem, we must understand that distance is the total length of path covered in a journey.

So;

Distance = 209km + 11km = 220km

The soft drink distributor covered 220km

3 0

3 years ago