Which is not a characteristic of an ideal fluid?

A cup containing 200 g of hot water is taken off the stove placed on the kitchen table. Initially the water is at 75Degree C. bu

8090 [49]

Answer:

ΔH = -45.1872 kJ , where negative sign signifies heat loss.

Q = ΔH = -45.1872 kJ , where negative sign signifies heat loss.

S system = -0.141 kJ/K

S surroundings = 0.1536 kJ/K

S universe = -0.141 kJ/K + 0.1536 kJ/K = 0.0126 kJ/K

Explanation:

Given:

Cp = 4. 184 J/(mole. K)

T₁ = 75 ⁰C

T₂ = 21 ⁰C

Mass of water = 200 g = 0.2 kg

Since,

$\Delta H=m\times C\times (T_f-T_i)$

ΔH = 0.2*4.184*(21-75) kJ

ΔH = -45.1872 kJ , where negative sign signifies heat loss.

Since the process is at constant pressure

Q = ΔH = -45.1872 kJ , where negative sign signifies heat loss.

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

T₁ = 75 ⁰C = 348 .15 K

T₂ = 21 ⁰C = 294.15 K

The entropy of the water is given by:

S = m×Cp×ln(T₂ /T₁)

S = 0.2*4.184*ln(294.15/348.15)

S system = -0.141 kJ/K

The heat gain by surroundings

dQ = -Qreaction = 45.1872 kJ

The entropy change of surroundings is

S surr = dQ/T₂ = 45.1872/294 .15

S surr = 0.1536 kJ/K

The entropy of universe is the sum total of the entropy of the system and the surroundings and thus,

S universe = Ssys + Ssurr

S universe = -0.141 kJ/K + 0.1536 kJ/K = 0.0126 kJ/K

4 0

3 years ago

Would a liquid’s refractive index measured at a high altitude be different from that measured at sea level?

Murrr4er [49]

By definition, refractive index is the ratio of the velocity of light in vacuum to the velocity of light in a specified medium. The medium here is the liquid. The speed of light through the liquid also depends on the temperature and pressure. At sea level, the liquid is higher in temperature and pressure. So, the speed is gonna be relatively slower because of the movement of atoms. At high altitude, the liquid is at a lower temperature and pressure. The movements of the molecules are lesser, thus, light can move much faster. So, yes, it would be different. The refractive index would be closer to 1 at high altitude, and greater than 1 at sea level.

6 0

3 years ago

A hydraulic press has a safety feature which consists of a hydraulic cylinder with a piston at one end and a safety valve at the

Sergio039 [100]

Answer:

Explanation:

radius of cylinder r₁ = .02 m

radius of safety valve r₂ = .0075 m

force exerted by spring on safety valve = 950 x .0085 = 8.075 N .

Force required on piston of cylinder = F

Applying Pascal's law

8.075 / 3.14 x .0075² = F / 3.14 x .02²

F = 8.075 x .02² / .0075²

= 8.075 x 7.111

= 57.42 N .

6 0

3 years ago

What is force magnifier

fredd [130]

Answer:

It is an instrument which increases the amount of force available to a single hypothetical person.

Examples;

Levers, pulleys are force magnifiers.

6 0

3 years ago

Nine tree lights are connected inparallel across 120-V potential difference. The cord to the wall socket carries a current of 0.

jok3333 [9.3K]

Answer:

a)3000ohm

b)4.44mA

Explanation:

a) we were given a Nine tree lights connected inparallel across 120-V potential difference, since the resistor are in parallel we use the expresion below

1/R(total)= 1/R₁ + 1/R₂ + 1/R₃ + 1/R₃ +.... 1/R₉

But according to ohm'law which can be expressed below

V=IR

R=V/I

R(total)= 120/0.36

= 333.33ohm

1/R(total)= 1/R₁ + 1/R₂ + 1/R₃ + 1/R₃ +.... 1/R₉

R₁=R₂ =R₃ =R₄= R₅=R₆=R₇=R₈=R₉

1/R(total)=9/R

1/333.33= 9/R

R= 3000ohm

Therefore, the resistance is 3000ohm

b)the bulbs were connected in series here, then for series connection we use below expression

R₁=R₂ =R₃ =R₄= R₅=R₆=R₇=R₈=R₉

R(total)=9R

= 9*3000

=27000ohm

I=VR

I=V/R

I= 120/27000

= 4.44*10⁻³A

4.44mA

Therefore, the current is 4.4mA

7 0

4 years ago