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3 years ago

Pascal's law tells us that, pressure is transmitted undiminished throughout an open container. a)- True b) False

Engineering

1 answer:

Naddik [55]3 years ago

8 0

Answer:

False

Explanation:

Pascal's law is not for open container it is for enclosed fluid

Pascal's law (also known as the principle of transmission of fluid pressue)

states that when pressure is applied at any part of an enclosed fluid it is transmitted undiminished throughout the fluid as well as to the walls of the container containing the fluid i.e., change in pressure at any point in an enclosed incompressible fluid is transmitted such that the same change occurs everywhere.

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A plane, opaque, surface M has the following properties: gray, diffuse, absorptivity = 0.7, surface area = 0.5 m2 , temperature

BaLLatris [955]

Answer:

The rate of energy absorbed per unit time is 3500W.

Explanation:

From the question, we were given the following parameters;

Plane, opaque, gray, diffuse surface

â = 0.7

Surface area, A = 0.5m²

Incoming radiant energy, G = 10000w/m²

T = 500°C

Rate of energy absorbed is âAG;

âAG = 0.7 × 0.5 × 10000

âAG = 3500W.

The energy absorbed is measured in watts and denoted by the symbol W.

7 0

3 years ago

A counter-flow double-piped heat exchange is to heat water from 20oC to 80oC at a rate of 1.2 kg/s. The heating is to be accompl

lawyer [7]

Answer:

110 m or 11,000 cm

Explanation:

let mass flow rate for cold and hot fluid = Mc and Mh respectively
let specific heat for cold and hot fluid = Cpc and Cph respectively
let heat capacity rate for cold and hot fluid = Cc and Ch respectively

Mc = 1.2 kg/s and Mh = 2 kg/s

Cpc = 4.18 kj/kg °c and Cph = 4.31 kj/kg °c

Using effectiveness-NUT method

First, we need to determine heat capacity rate for cold and hot fluid, and determine the dimensionless heat capacity rate

Cc = Mc × Cpc = 1.2 kg/s × 4.18 kj/kg °c = 5.016 kW/°c

Ch = Mh × Cph = 2 kg/s × 4.31 kj/kg °c = 8.62 kW/°c

From the result above cold fluid heat capacity rate is smaller

Dimensionless heat capacity rate, C = minimum capacity/maximum capacity

C= Cmin/Cmax

C = 5.016/8.62 = 0.582

.2 Second, we determine the maximum heat transfer rate, Qmax

Qmax = Cmin (Inlet Temp. of hot fluid - Inlet Temp. of cold fluid)

Qmax = (5.016 kW/°c)(160 - 20) °c

Qmax = (5.016 kW/°c)(140) °c = 702.24 kW

.3 Third, we determine the actual heat transfer rate, Q

Q = Cmin (outlet Temp. of cold fluid - inlet Temp. of cold fluid)

Q = (5.016 kW/°c)(80 - 20) °c

Qmax = (5.016 kW/°c)(60) °c = 303.66 kW

.4 Fourth, we determine Effectiveness of the heat exchanger, ε

ε = Q/Qmax

ε = 303.66 kW/702.24 kW

ε = 0.432

.5 Fifth, using appropriate effective relation for double pipe counter flow to determine NTU for the heat exchanger

NTU = $\\ \frac{1}{C-1} ln(\frac{ε-1}{εc -1} )$

NTU = $\frac{1}{0.582-1} ln(\frac{0.432 -1}{0.432 X 0.582 -1} )$

NTU = 0.661

.6 sixth, we determine Heat Exchanger surface area, As

From the question, the overall heat transfer coefficient U = 640 W/m²

As = $\frac{NTU C{min} }{U}$

As = $\frac{0.661 x 5016 W. °c }{640 W/m²}$

As = 5.18 m²

.7 Finally, we determine the length of the heat exchanger, L

L = $\frac{As}{\pi D}$

L = $\frac{5.18 m² }{\pi (0.015 m)}$

L= 109.91 m

L ≅ 110 m = 11,000 cm

3 0

3 years ago

If a worker currently makes $425.00 per week, what Is the gross amount they’ll earn if they work every week of the year

olga nikolaevna [1]

Answer:

we know that

A worker currently makes \$425.00 per week

remember that

1\ year=52\ weeks

by proportion find the amount that the worker will earn in one year

\frac{425}{1} \frac{\$}{week} =\frac{x}{52} \frac{\$}{weeks} \\ \\x=52*425 \\ \\x=\$22,100

therefore

the answer is

\$22,100

Explanation:

4 0

3 years ago

Many manufacturers currently offer SAE level _________ equipped vehicles

Pepsi [2]

Answer should be B.3 hopefully

7 0

3 years ago

A vertical plate is partially submerged in water and has the indicated shape. The height is 3m, the width at the top is 4m, and

natka813 [3]

Answer: 1.98 × 10^4 N

Explanation:

Form similar triangle ADE and ABC

a/x= 2/3, a=2/3x

Width of the strip w= 2(4+a) = 8+2a

W= 8 +2 (2/3x)= 8+4/3x

Area of the strip = w Δx

(8 +4/3x) Δx

Pressure on the strip p= pgx= 10^3 ×9.81x= 9810x

But,

Force= Pressure × area= 9810x × (8+4/3x)Δx

Adding the forces and taking lim n to infinity

F total= lim n--> infinity E 9810x × (8+4/3x)Δx

Ftotal= Integral 2,0 9810x × (8+4/3x)Δx

F total= 9810 integral 2, 0 (8+4/3x)dx

= 9810(8+x^2/2 + 4/3x^3/3)2,0

=9810(4x^2 + 4/9x^3)

=9810(4x2^2 + 4/9×2^3-0)

=9810(16 + 32/9)

Hydrostatic force as an integral

Ft= 19.18 ×10^4N

7 0

3 years ago