Ask question

Ask question

All categories

2 years ago

10

In a heat-treating process, a 1-kg metal part, initially at 1075 K, is quenched in a closed tank containing 100 kg of water, ini

tially at 295 K. There is negligible heat transfer between the contents of the tank and their surroundings. Modeling the metal part and water as incompressible with constant specific heats 0.5 kJ/kg K and 4.4 kJ/kg K, respectively, determine the final equilibrium temperature after quenching, in K.

1 answer:

storchak [24]2 years ago

8 0

Answer:

attached below

Explanation:

You might be interested in

In several sentences, please discuss:

Bezzdna [24]

Answer:

Everything is explained below in the Explanation section.

Explanation:

<em>a) TMDL stands for = Total Daily Maximum Loads</em>

TMDL is the measure of total maximum amount of pollutant allowed in the water body. TMDL is a important tool to maintain the quality of water and measure the aquatic pollution.

Whereas, the formula to calculate TMDL is as follows:

TMDL = Sum of waste load allocations (point source) + Sum of load allocations (non point sources and background) + Margin of Safety

<em>b) Dead Zones :</em>

Dead zones are zones which are termed as hypoxic which are low in oxygen because of the extreme aquatic pollution caused by human activities which in result deplete the oxygen level above the and below the oceans most required by the marine life. In addition, dead zones are those areas where oxygen is low and life in danger is high comparatively to other areas of oceans.

The main cause of that dead zones is because of eutrophication which means adding dangerous chemical nutrients in the water in exceeding amounts.

<em>c) Why Ammonia-nitrogen is detrimental to waterbodies: </em>

1. Ammonia nitrogen is a very toxic pollutant often found in landfills and sewage and waste products.

2. Ammonia nitrogen reduces the ability of water to disinfect its inhabitants and it reduces the purity. Furthermore, it changes the smell of the water and pollutes it.

3. Last but not the least, if you increase the concentration of ammonia nitrogen, the dissolved oxygen rate will be decreased and it has a inverse relation which is very dangerous to marine life underwater.

<em>d) Streeter-Phelps DO curve:</em>

Please refer to the attachment, I have attached the curve.

This curve is used to evaluate the dissolved oxygen in the water with varying distance.

It can be further studied from the curve that, how much loss sewage and other pollutants can endure upon the marine life.

8 0

3 years ago

Which of these are not included as part of a drivetrain

Zielflug [23.3K]

Answer:

transmission, driveshafts, differential and axles

Explanation:

The powertrain consists of the prime mover (e.g. an internal combustion engine and/or one or more traction motors) and the drivetrain - all of the components that convert the prime mover's power into movement of the vehicle (e.g. the transmission, driveshafts, differential and axles); whereas the drivetrain does not.

7 0

2 years ago

A pin connection supports a load. Which type of connection would result in the smallest shear stress in the pin

Viktor [21]

Answer:

A single- shear pin connection.

Explanation:

8 0

1 year ago

A 50 Hz, four pole turbo-generator rated 100 MVA, 11 kV has an inertia constant of 8.0 MJ/MVA. (a) Find the stored energy in the

raketka [301]

Given Information:

Frequency = f = 60 Hz

Complex rated power = G = 100 MVA

Intertia constant = H = 8 MJ/MVA

Mechanical power = Pmech = 80 MW

Electrical power = Pelec = 50 MW

Number of poles = P = 4

No. of cycles = 10

Required Information:

(a) stored energy = ?

(b) rotor acceleration = ?

(c) change in torque angle = ?

(c) rotor speed = ?

Answer:

(a) stored energy = 800 Mj

(b) rotor acceleration = 337.46 elec deg/s²

(c) change in torque angle (in elec deg) = 6.75 elec deg

(c) change in torque angle (in rmp/s) = 28.12 rpm/s

(c) rotor speed = 1505.62 rpm

Explanation:

(a) Find the stored energy in the rotor at synchronous speed.

The stored energy is given by

$E = G \times H$

Where G represents complex rated power and H is the inertia constant of turbo-generator.

$E = 100 \times 8 \\\\E = 800 \: MJ$

(b) If the mechanical input is suddenly raised to 80 MW for an electrical load of 50 MW, find rotor acceleration, neglecting mechanical and electrical losses.

The rotor acceleration is given by

$P_a = P_{mech} - P_{elec} = M \frac{d^2 \delta}{dt^2}$

Where M is given by

$M = \frac{E}{180 \times f}$

$M = \frac{800}{180 \times 50}$

$M = 0.0889 \: MJ \cdot s/ elec \: \: deg$

So, the rotor acceleration is

$P_a = 80 - 50 = 0.0889 \frac{d^2 \delta}{dt^2}$

$30 = 0.0889 \frac{d^2 \delta}{dt^2}$

$\frac{d^2 \delta}{dt^2} = \frac{30}{0.0889}$

$\frac{d^2 \delta}{dt^2} = 337.46 \:\: elec \: deg/s^2$

(c) If the acceleration calculated in part(b) is maintained for 10 cycles, find the change in torque angle and rotor speed in revolutions per minute at the end of this period.

The change in torque angle is given by

$\Delta \delta = \frac{1}{2} \cdot \frac{d^2 \delta}{dt^2}\cdot (t)^2$

Where t is given by

$1 \: cycle = 1/f = 1/50 \\\\10 \: cycles = 10/50 = 0.2 \\\\t = 0.2 \: sec$

So,

$\Delta \delta = \frac{1}{2} \cdot 337.46 \cdot (0.2)^2$

$$ \Delta \delta = 6.75 \: elec \: deg$

The change in torque in rpm/s is given by

$\Delta \delta = \frac{337.46 \cdot 60}{2 \cdot 360\circ }$

$\Delta \delta =28.12 \: \: rpm/s$

The rotor speed in revolutions per minute at the end of this period (10 cycles) is given by

$Rotor \: speed = \frac{120 \cdot f}{P} + (\Delta \delta)\cdot t$

Where P is the number of poles of the turbo-generator.

$Rotor \: speed = \frac{120 \cdot 50}{4} + (28.12)\cdot 0.2$

$Rotor \: speed = 1500 + 5.62$

$$ Rotor \: speed = 1505.62 \:\: rpm$

4 0

3 years ago

What affect results when there is an impact between earth and is astroids check all that apply.

Vadim26 [7]

Answer:

Massive destruction

Explanation:

If the asteroid collides with the ground, a massive volume of dust will be blasted into the environment. If it collides with water, the amount of water vapour in the atmosphere will rise. This would result in more rain, which would cause earthquakes and mudslides.

As the asteroid collided with the Earth, massive volumes of dust were ejected into to the atmosphere. The sun's light were stopped from entering the Earth's surface, which is terrible news for plants.

6 0

2 years ago