A disk-shaped part is to be cast out of aluminum. The diameter 500 mm and thickness = 20 mm. If the mold constant = 3.0 s/mm2 in Chvorinov's Rule, how long will it take the casting to solidify, in minutes?

Answers

Answer 1

Answer:

t =253.8s

Explanation:

Chvorinov's Rule can be written as:

[tex]t=B(\frac{V}{A} )^{n}[/tex]

where t is the solidification time,

V is the volume of the casting,

A is the surface area of the casting that contacts the mold,

n is a constant

B is the mold constant

The S.I. units of the mold constant B are s/m2.

According to Askeland, the constant n is usually 2.

[tex]V=\frac{\pi D^{2}h }{4} = 3.9*10^6[/tex]mm3

[tex]As=\pi D h+2\frac{\pi }{4} D^{2} =0.424*10^6[/tex] mm2

[tex]V/A=9.198[/tex]mm

[tex]t = 3.0*9.198^2[/tex] =253.8s

Answer 2

Answer:

Chvorinov's Rule with Askeland Method: t = 4.286694102 minutes

Chvorinov's Rule with Degarmo Method:

Minimum time required at constant n = 1.5 : t = 1.408751434 minutesMaximum time required at constant n = 2.0 : t = 4.286694102 minutes

Explanation:

Data:

Aluminum disc

Diameter (D) = 500 mm

Thickness = Height (h) = 20 mm

Mold Constant (C) = 3.0 sec / [tex]mm^{2}[/tex]

Required:

Solidification time (t) in minutes = ?

Formula:

The solidification time can be found by using the Chvorinov's Rule:

[tex]t = C (\frac {V}{A})^{n}[/tex]

Where;

t = solidification time

C = mold constant

V = Volume of disc

A = Surface area of disc

n = constant

Note: According to Askeland n = 2.0 and According to Degarmo n varies 1.5 to 2.0 therefore , we will do for both method and by Degarmo method we can predict maximum and minimum solidification time.

Solution:

First, we will find the volume of the disc

disc = cylinder

therefore, Volume of cylinder is given by:

[tex]V = \frac{\pi }{4} * D^{2} * H[/tex]

Where:

V = Volume of Cylinder

H = Height of disc

D = Diameter of disc

Now, putting dimensional values in above equation

[tex]V = \frac{\pi }{4} * 500^{2}  *20[/tex]

V = 3926990.817 [tex]mm^{3}[/tex]

Second, we will find the surface area of the disc

Therefore, surface area of cylinder is given by:

[tex]A = (\pi * D * H) + (2 * \frac{\pi }{4} * D^{2} )[/tex]

Where:

A = Surface area of disc

D = Diameter of disc

H = Height of disc

Now, putting dimensional values in above equation

[tex]A = (\pi * 500 * 20) + (2 * \frac{\pi }{4} * 500^{2} )[/tex]

A = 424115.0082 [tex]mm^{2}[/tex]

Finally, Moving towards the final solution

Chvorinov's Rule with Askeland Method n = 2:

Rewriting the equation:

[tex]t = C (\frac {V}{A})^{2}[/tex]

Putting the dimensional and constants values in the equation

[tex]t = 3.0 (\frac {3926990.817}{424115.0082})^{2}[/tex]

t = 257.2016461 seconds

Converting to minutes

t = 4.286694102 minutes

Chvorinov's Rule with Degarmo Method n = 1.5 (Minimum Solidification Time)

Rewriting the equation:

[tex]t = C (\frac {V}{A})^{2}[/tex]

Putting the dimensional and constants values in the equation

[tex]t = 3.0 (\frac {3926990.817}{424115.0082})^{1.5}[/tex]

t = 84.52508604 seconds

Converting to minutes

t = 1.408751434 minutes

Chvorinov's Rule with Degarmo Method n = 2.0 (Maximum Solidification Time)

Rewriting the equation:

[tex]t = C (\frac {V}{A})^{2}[/tex]

Putting the dimensional and constants values in the equation

[tex]t = 3.0 (\frac {3926990.817}{424115.0082})^{2}[/tex]

t = 257.2016461 seconds

Converting to minutes

t = 4.286694102 minutes


Related Questions

An object of mass 521 kg, initially having a velocity of 90 m/s, decelerates to a final velocity of 14 m/s. What is the change in kinetic energy of the object, in kJ?

Answers

Answer:2058.992KJ

Explanation:

Given data

Mass of object[tex]\left ( m\right )[/tex]=521kg

initial velocity[tex]\left ( v_0\right )[/tex]=90m/s

Final velocity[tex]\left ( v\right )[/tex]=14m/s

kinetic energy of body is given by=[tex]\frac{1}{2}[/tex][tex]m[/tex][tex]v^{2}[/tex]

change in kinectic energy is given by substracting  final kinetic energy from initial kinetic energy of body.

Change in kinetic energy=[tex]\frac{1}{2}\times m[/tex][tex]\left ( V_0^{2}-V^2\right )[/tex]

Change in kinetic energy=[tex]\frac{1}{2}\times521[/tex][tex]\left ( 90^{2}-14^2\right )[/tex]

Change in kinetic energy=2058.992KJ

What is the no-slip condition? What causes it?

Answers

The no-slip condition is the viscosity of a fluid.This is most likely brought on by stress or stressful situations.

Answer/Explanation:

The no-slip condition for viscous fluids assumes that at a solid boundary, the fluid will have zero velocity relative to the boundary. Along with a flow when adhesion is stronger than cohesion. ... Basically the molecules of the fluid crash into the molecules of the wall and get stopped.

The "view factor" Fij depends on surface emissivity and surface geometry. a) True b) False

Answers

Answer:

(B) FALSE

Explanation:

view factor [tex]F_{ij}[/tex] depends on the surface emissivity and the surface of geometry  view factor is the term used in radiative heat transfer. View factor is depends upon the radiation which leave the surface and strike the surface.View factor is also called shape factor configuration factor it is denoted by  [tex]F_{ij}[/tex]

The use of zeroes after a decimal point are an indicator of accuracy. a)True b)- False

Answers

Answer:

True.

Explanation:

Yes, zeroes indicates the precision  after the decimal point.

For smallest of the calculation in to get the precise value is very important for that the calculation can have very minute changes in decimal point as more accurate the calculation  is more zeroes will be in the decimal value .

Most of the instrument calculating weights is said to precise by how much decimal they can calculate.

A spherical steel container 3 feet in diameter is buried in a land fill. The container is filled with a chemical that keeps the outer surface of the container at 100°F, whereas the earth's surface is at 50°F. Determine the heat transfer from the container if it is buried under 3 feet of earth.

Answers

Answer:

Q = 378.247 Bt/hr

Explanation:

given data:

diameter of container = 3 m

so r =  1.5 m

T1 = 50°C

T2 = 100°C

depth y = 3 ft

Heat transfer is given as Q

[tex]Q = SK\Delta T[/tex]

Where

S =  Shape factor for the object

[tex]S = \frac{4\pi r}{1-\frac{r}{2y}}[/tex]

[tex]S = \frac{4\pi *1.5}{1-\frac{1.5}{2*3}}[/tex]

S = 25.132 ft

[tex]Q = SK\Delta T[/tex]

Q = 25.132*0.301 *(100-50)

Q = 378.247 Bt/hr

A mass of 7 kg undergoes a process during which there is heat transler frorn the mass at a rate of 2 kJ per kg, an elevation decrease of 40 m, and an increase in velocity from 13 m/s to 23 m/s. The specific internal energy decreases by 4 kJ/kg and the acceleration of gravity is constant at 9.7 m/s2. Determine the work for the process, in k.J

Answers

Answer:44.61 KJ

Explanation:

Let h_1,V_1,Z_1 be the initial specific enthalpy,velocity&elevation of the system

and h_2,V_2,Z_2 be the Final specific enthalpy,velocity&elevation of the system

mass(m)=7kg

Applying Steady Flow Energy Equation

[tex]m\left [ h_1+\frac{v_1^2}{2g}+gZ_1\right ][/tex]+Q=[tex]\left [ h_2+\frac{v_2^2}{2g}+gZ_2\right ][/tex]+W

[tex]h_1-h_2=4 KJ/kg[/tex]

[tex]V_1=13m/s[/tex]

[tex]V_2=23m/s[/tex]

[tex]Z_1-Z_2=40m[/tex]

substituting values

[tex]7\left [ h_1+\frac{13^{2}}{2g}+gZ_1\right ]+7\times2[/tex] = [tex]\left [ h_2+\frac{23^2}{2g}+gZ_2\right ][/tex]+W

W=[tex]7\left [h_1-h_2+\frac{V_1^2-V_2^2}{2000g}+g\frac{\left (Z_1-Z_2 \right )}{1000}\right ][/tex]+Q

W=[tex]7\left [4+\frac{13^2-23^2}{2000g}+g\frac{\left (40 \right )}{1000}[\right ][/tex]+[tex]2\times 7[/tex]

W=44.61KJ

The equation of motion is not valid without the assumption of an inertial frame. a) True b)- false

Answers

Answer:

True

Explanation:

when we write equation of motion we have to assume frame of reference as because frame of reference  is the property that in frame of reference the body is not accelerated and net force acting on the body is zero.

when body is assumed to be any frame of reference we can assume the body is at rest and moving with constant speed.

Answer:

true

Explanation:

hope this helped , God bless

List fabrication methods of composite Materials.

Answers

Answer:

Fabrication method of composite materials varies for one product of material to other product. It is basically developed to meet the product requirement.

The fabrication of composite parts are depends upon different factors that are:

Depend on the Characteristics of strengthening and matrices. The details of the product and the shape and size also.Application or end uses.

Types of fabrication methodologies are :

Press moldingCompression moldingContact moldOpen molding Tube rolling

A Carnot refrigeration cycle absorbs heat at -12 °C and rejects it at 40 °C. a)-Calculate the coefficient of performance of this refrigeration cycle b)-If the cycle is absorbing 15 kW at the -12C temperature, how much power is required? c)-If a Carnot heat pump operates between the same temperatures as the above refrigeration cycle, determine the COP of heat pump? d)-What is the rate of heat rejection at the 40°C temperature if the heat pump absorbs 15 kw at the -12 C temperature?

Answers

Answer:

a)COP=5.01

b)[tex]W_{in}=2.998[/tex] KW

c)COP=6.01

d)[tex]Q_R=17.99 KW[/tex]

Explanation:

Given

[tex]T_L[/tex]= -12°C,[tex]T_H[/tex]=40°C

For refrigeration

  We know that Carnot cycle is an ideal cycle that have all reversible process.

So COP of refrigeration is given as follows

[tex]COP=\dfrac{T_L}{T_H-T_L}[/tex]  ,T in Kelvin.

[tex] COP=\dfrac{261}{313-261}[/tex]

a)COP=5.01

Given that refrigeration effect= 15 KW

We know that  [tex]COP=\dfrac{RE}{W_{in}}[/tex]

RE is the refrigeration effect

So

5.01=[tex]\dfrac{15}{W_{in}}[/tex]

b)[tex]W_{in}=2.998[/tex] KW

For heat pump

So COP of heat pump is given as follows

[tex]COP=\dfrac{T_h}{T_H-T_L}[/tex]  ,T in Kelvin.

[tex] COP=\dfrac{313}{313-261}[/tex]

c)COP=6.01

In heat pump

Heat rejection at high temperature=heat absorb at  low temperature+work in put

[tex]Q_R=Q_A+W_{in}[/tex]

Given that [tex]Q_A=15[/tex]KW

We know that  [tex]COP=\dfrac{Q_R}{W_{in}}[/tex]

[tex]COP=\dfrac{Q_R}{Q_R-Q_A}[/tex]

[tex]6.01=\dfrac{Q_R}{Q_R-15}[/tex]

d)[tex]Q_R=17.99 KW[/tex]

Modified Reynolds Analogy is often used in the Heat Exchanger industry. a) True b) False

Answers

Answer: True

Explanation: Modified Reynolds Analogy is based on heat transfer process in the Plate Heat Exachanger's(PHE) which is done in the phases that have complex form plates shape by being changed into sheet metal. This analogy helps in the increment of the reliability and operation to be carried out easily in the  industries.Thus the given statement is true.

If a point is positioned 16 inches from the origin on the x-y plane, and it is 12 inches above the x axis, what is its position in terms of the unit vectors i and j?

Answers

Answer:

[tex]p=12\hat{i}+10.58\hat{j}[/tex]

Explanation:

distance of point from the origin is 16 inch

x-axis distance =12 inch

[tex]p=\sqrt{x^2+y^2[/tex]

[tex]y=\sqrt{p^2-x^2} \\y=\sqrt{16^2-12^2}\\ y=\sqrt{112}[/tex]

y=10.58 inch

[tex]p=12\hat{i}+10.58\hat{j}[/tex]

What is the advantage to use a multistage compression refrigeration system over a single stage compression system?

Answers

Answer:

the advantages of using multistage compression refrigeration system over a single stage compression system are as follows:

Explanation:

It results in increased volumetric efficiency of compressor due to decrease in pressure ratio in each stage.Cost of operation is comparatively lowUniformity in torque is achieved thus reducing the size of the flywheel.Reduced size of condensor as a result of heat removal during condensationLower temperature at the end of compression resulting in effective lubrication and increased compressor life.

List irreversibilities

Answers

Answer:

Some of the irreversibilities are listed below:

Plastic deformation of solidsTransfer of heat over finite difference of temperatureWhen two fluids are mixed together the process is irreversibleCombustion of a gasCurrent flowing through a finite resistor Diffusion and free compression or expansion of gasRelative motion of body with force of frictionProcesses involving chemical reactions(spontaneous)

Cylinder cushions at the ends of the cylinder speeds the piston up at the end of the stroke. a)- True b) False

Answers

The answer is True.

The turbine blade tip speed v for r=1m and 5 rev/sec is a) 5 m/s b) 0.25 m/s c) 0.20 m/s

Answers

Answer:

(a) 5 m/sec

Explanation:

we have given r=1 meter

angular velocity ω =5 revolution/sec

we have to find the velocity of turbine blade tip

the velocity of turbine blade tip is given by v =rω

where v = velocity of turbine blade tip

           r = radius

          ω = angular velocity

so v =5×1= 5 meter/sec

so the option (a) will be the correct option as in option (a) velocity is given as 5 meter/sec

What is the difference between a refrigeration cycle and a heat pump cycle?

Answers

Answer:

In refrigeration cycle heat transfer from inside refrigeration

In heat pump cycle heat transfer from environment

Explanation:

heat cycle is mechanical process use for cool the temperature but

In refrigeration heat transfer from inside of refrigeration that decrease temperature of refrigerator and in heat pump it decrease temperature negligible as compare to refrigerator

A cubic transmission casing whose side length is 25cm receives an input from the engine at a rate of 350 hp. If the vehicle's velocity is such that the average heat transfer coefficient is 230 W/m'K and the efficiency of the transmission is n=0.95 (i.e. the remainder is heat), calculate the surface temperature if the ambient temperature is 15°C. Assume that heat transfer only occurs on one face of the cube. NOTE: 1 hp=745 W

Answers

Answer:

The surface temperature is 921.95°C .

Explanation:

Given:

   a=25 cm ,P=350 hp⇒P=260750 W

Power transmitted [tex]0.95\times 260750[/tex]W and remaining will lost in the form of heat.This heat transmitted to air by the convection.

 h=230[tex]\frac{W}{m^2-K},\eta =0.95[/tex]

Actually heat will be transmit by the convection.

In convection Q=hA[tex]\Delta T[/tex]

So [tex]P=\Delta T\times Q[/tex]

[tex]0.05\times 260750=230\times0.25^2\(T-15)[/tex]

T=921.95°C

So the surface temperature is 921.95°C .

The area under the moment diagram is shear force. a)-True b)-False

Answers

Answer:

False

Explanation:

as we know that [tex]V(x)=\frac{dM}{dx}\\ \\=> M(x) = \int\limits^x_o {V(x)} \, dx \\\\[/tex]

=> Area under shear diagram gives the moment at any point but the reverse cannot be established from the same relation

Air is compressed in an isentropic process from an initial pressure and temperature of P1 = 90 kPa and T1=22°C to a final pressure of P2=900 kPa. Determine: a)- The final temperature of the air. b)-The work done per kg of air during the process.

Answers

Answer:

a) [tex]T_2=569.35 K[/tex]

b)Work done per kg of air=196.84 KJ/Kg

Explanation:

Given: [tex]\gamma =1.4[/tex] for air.

[tex]P_1=90 KPa ,T_=22^\circ C,P_2=900 KPa[/tex]

We know that  

[tex]\dfrac{T_2}{T_1}=\left (\frac{P_2}{P_1}\right )^{\dfrac{{\gamma-1}}{\gamma}}[/tex]

So  [tex]\dfrac{T_2}{295}=\left (\frac{900}{90}\right )^{\dfrac{{1.4-1}}{1.4}}[/tex]

[tex]T_2=569.35 K[/tex]

(a) [tex]T_2=569.35 K[/tex]

(b)Work for adiabatic process

  W=[tex]\frac{P_1V_1-P_2V_2}{\gamma -1}[/tex]

We know that PV=mRT for ideal gas.

 W=[tex]mR\frac{T_1-T_2}{\gamma -1}[/tex]

Now by putting values

work per kg of air=[tex]0.287\times \frac{295-569.35}{1.4 -1}[/tex]

Work w=-196.84 KJ/Kg    (Negative sign indicate work given to input.)

So work done per kg of air=196.84 KJ/Kg

The Poisson effect does not apply to shear strains. a)True b)- False

Answers

Answer:

true

Explanation:

Shear strains and direct strains are independent components in a strain tensor at a point. Also the poisson ratio is defined as

μ = - [tex]\frac{lateral strain}{longitudinal strain}[/tex]

Which is independent of shear strains Thus this affect does not apply on shear strains

The shear force diagram is always the slope of the bending moment diagram. a)True b)- False

Answers

Answer:

True

Explanation:

Shear force diagram is a diagram which is drawn by calculating the shear force either to the right of the section or to the left of the section .

shear force is also be define as the change of moment w.r.t to distance

                              V=[tex]\frac{\mathrm{d}M }{\mathrm{d} x}[/tex]

where V is shear force and M is bending moment.

from the equation we can clearly say that shear force diagram is slope of bending moment diagram.

As the car gets older, will its engine's compression ratio change, if yes how.

Answers

Answer:

yes

Explanation:

yes, it is correct as car gets older  the engine's compression ratio changes .

compression ratio is the volume in maximum compression chamber to the volume in the piston at full compression .

More and more engine will be used if the ring wears compression goes down

or there can be one condition if carbon build up on the piston then this can alter the compression ratio.

What does STP and NTP stands for in temperature measurement?

Answers

STP stands for standard temperature pressure and NTP stands for normal temperature pressure

Describe the basic types of chips produced in metal-cutting operations.

Answers

Answer:

Chips are of three types --

1. Continuous chip

2. Discontinuous or segmental chip

3.  Continuous chip with built up edge

Explanation:

Conventional machining process always removes some excess part of the metal in the form of Chips. Every machinist should be well aware of the type of chip formed as it gives the knowledge of the machining process. The chips forms give the knowledge of --

1. Dimension of tool

2. feed rate

3. cutting speed

4. nature of tool

5. Friction between tool and work piece

the different types of chips are :

1. Continuous chips :

  Continuous chips are long ribbon like coil that are bonded together. The continuous chips undergoes plastic deformation continuously. This is the most desirable form of chip produced. When such chips are formed, the  cutting is smooth with good surface finish. Mostly ductile material forms continuous chips.

2. Discontinuous chips :

   Discontinuous chips are formed when metals are machined and the material gets deformed easily. Brittle materials forms discontinuous chips. Discontinuous chips are in the form of loose broken chips that are not continuous. Discontinuous chips are formed when depth of cut and feed is large and cutting sped is low.

3. Continuous chips with built up edge :

   These chips are similar to the continuous chips where surface finish is not smooth. When ductile materials are machined at low cutting speed, a portion of work material tends tends to stick at the rake face of the tool due to the friction between the tools and the chip. This is known as built up edge.

A student checks her car's tyre air pressure at a petrol station and finds it is 31 psi. Re-express this as an absolute pressure in kpa. Note any assumptions you make.

Answers

Answer:

Absolute Pressure=315.06256 kPa

Explanation:

Gauge pressure= 31 psi

Atmospheric Pressure at Sea level= 1 atm=101.325 kPa

[tex]1\ psi=6.89476\ kPa\\\Rightarrow 31\ psi=31\times 6.89476\\\Rightarrow 31\ psi=213.73756\ kPa=Gauge\ Pressure\\Absolute\ Pressure=Gauge\ Pressure+Atmospheric\ Pressure\\\Rightarrow Absolute\ Pressure=213.73756+101.325\\\therefore Absolute\ Pressure=315.06256\ kPa[/tex]

A free particle has kinetic energy equal to 35eV a)- What is the velocity of the particle? b)- If this velocity is known to within 0.2% accuracy, what is r of the position that particle? Assume that the mass of the particle is 2 x 10^-26 kg. Use h and give the answer in nm.

Answers

Given:

kinetic energy of free particle, KE = 35ev

1eV = [tex]1.6\times 10^{-19}[/tex] J

mass of the particle, m = [tex]2\times 10^{-26}[/tex] Kg

accuracy in velocity= 0.2%= 0.002

Solution:

a) We know that

KE = [tex]\frac{1}{2}mv^{2}[/tex]

v = [tex]\sqrt{\frac{2KE}{m}}[/tex]

⇒ v = [tex]\sqrt{\frac{2\times 35\times1.6\times 10^{-19} }{2\times 10^{-26}}}[/tex]

v = [tex]2.36\times10^{4}[/tex] m/s

b) From Heisenberg's uncertainity principle:

[tex]\Delta x\Delta p = \frac{h}{4\pi}[/tex]

[tex]\Delta x.(mv) = \frac{h}{4\pi}[/tex]

[tex]\Delta x = \frac{h}{4\pi\times 2\times 10^{-26}\times2.36 \times 10^{4}\times 0.002}[/tex]

[tex]\Delta x = 0.56nm[/tex]

If 100 J of heat is added to a system so that the final temperature of the system is 400 K, what is the change in entropy of the system? a)- 0.25 J/K b)- 2.5 J/K c)- 1 J/K d)- 4 J/K

Answers

Answer:

0.25 J/K

Explanation:

Given data in given question

heat (Q) = 100 J

temperature (T) = 400 K

to find out

the change in entropy of the given system

Solution

we use the entropy change equation here i.e  

ΔS = ΔQ / T           ...................a

Now we put the value of heat (Q) and Temperature (T) in equation a

ΔS is the entropy change, Q is heat and T is the temperature,  

so that

ΔS = 100/400 J/K

ΔS = 0.25 J/K

An experimentalist claims that, based on his measurements, a heat engine receives 300 Btu of heat from a source of 900 R, converts 160 Btu of it to work, and rejects the rest as waste heat to a sink at 540 R. Are these measurements reasonable? Why?

Answers

The maximum efficiency must be greater than the actual efficiency of the heat engine. These measurements are not reasonable.

What is Efficiency?

The efficiency is defined as the work done by the engine divided by the heat supplied.

So, maximum efficiency η = 1 - T₁/T₂ = W/Qs

Where T₁ is the lower temperature and T₂ is the higher temperature.

An experimentalist claims that, based on his measurements, a heat engine receives 300 Btu of heat from a source of 900 R, converts 160 Btu of it to work, and rejects the rest as waste heat to a sink at 540 R

Substitute the value into the expression , we get

η = 1 -(540 / 900) x 100 %

η = 40 %

η  = Work done/heat supplied

Substitute the value into the expression , we get

η = 160/300 x 100 %

η = 53 %

So, the maximum efficiency must be greater than the actual efficiency of the heat engine.

Thus, these measurements are not reasonable.

Learn more about efficiency.

https://brainly.com/question/13828557

#SPJ2

Final answer:

The experimentalist's claim that the heat engine converts more work than allowed by the Carnot efficiency is not reasonable because it exceeds the theoretical maximum efficiency, violating the second law of thermodynamics.

Explanation:

The experimentalist's claim that a heat engine receives 300 Btu of heat from a source at 900 R, converts 160 Btu of it to work, and rejects the rest as waste heat to a sink at 540 R can be assessed using the second law of thermodynamics and the concept of Carnot efficiency. The Carnot efficiency can be calculated using the temperatures of the hot and cold reservoirs (Th and Tc):

Carnot Efficiency (EffC) = 1 - (Tc/Th)

Assuming the temperatures are in degrees Rankine (where 0 R is absolute zero), we can calculate the maximum theoretical efficiency for a perfectly reversible engine:

EffC = 1 - (540 R / 900 R) = 1 - 0.6 = 0.4 (or 40%)

However, the experimentalist's claim states that 160 Btu is converted to work out of the 300 Btu received, which represents an actual efficiency (EffA) of:

EffA = Work done / Heat received = 160 Btu / 300 Btu = 0.5333 (or 53.33%)

Since the actual efficiency (53.33%) claimed by the experimentalist exceeds the maximum possible Carnot efficiency (40%) for a heat engine operating between these temperatures, the experimentalist's measurements are not reasonable and violate the second law of thermodynamics.

Define the terms (a) thermal conductivity, (b) heat capacity and (c) thermal diffusivity

Answers

Explanation:

(a)

The measure of material's ability to conduct thermal energy (heat) is known as thermal conductivity. For examples, metals have high thermal conductivity, it means that they are very efficient at conducting heat. The SI unit of heat capacity is W/m.K.

The expression for thermal conductivity is:

[tex]q=-\kappa \bigtriangledown T[/tex]

Where,

q is the heat flux

[tex]\kappa[/tex] is the thermal conductivity

[tex] \bigtriangledown T[/tex] is the temperature gradient.

(b)

Heat capacity for a substance is defined as the ratio of the amount of energy required to change the temperature of the substance and the magnitude of temperature change. The SI unit of heat capacity is J/K.

The expression for Heat capacity is:

[tex]C=\frac{E}{\Delta T}[/tex]

Where,

C is the Heat capacity

E is the energy absorbed/released

[tex]\Delta T[/tex] is the change in temperature

(c)

Thermal diffusivity is defined as the thermal conductivity divided by specific heat capacity at constant pressure and its density. The Si unit of thermal diffusivity is m²/s.

The expression for thermal diffusivity is:

[tex]\alpha=\frac{\kappa}{C_p \times \rho}[/tex]

Where,

[tex]\alpha[/tex] is thermal diffusivity

[tex]\kappa[/tex] is the thermal conductivity

[tex]C_p[/tex] is specific heat capacity at constant pressure

[tex]\rho[/tex] is density

What is the function of the following: 1- Oil rings 2- Flywheel 3- Timing gears

Answers

Answer:

Explanation:

The functions of the following are as follows:

1). Oil Rings:

Regulates oil within cylinder walls.Helps to keep cylinder walls lubricatedPrevent Heat transferReduce friction between piston and cylinder

2). Fly Wheel:

It is used to store rotational energyIt resist any change in rotational speed due to its moment of inertiaIt helps to control the orientation of the mechanical system

3). Timing gears:

It provides synchronization in the rotation of crankshaft and the camshaft so as to provide proper valve opening and closing time during each cylinder's stroke(intake and exhaust).
Other Questions
WANT FREE 20 POINTS + BRAINLIEST? answer this geometry question correct and i got you Which statements are true based on the diagram? Select three options. A. Points N and K are on plane A and plane S. B. Points P and M are on plane B and plane S. C. Point P is the intersection of line n and line g. D. Points M, P, and Q are noncollinear. E. Line d intersects plane A at point N. All the following would be a reason for a business to expand EXCEPT romper (con) : una pareja termina la relacin Question 1 with 1 blank : dar un regalo Question 2 with 1 blank : una comida fra y dulce Question 3 with 1 blank : dos personas enamoradas Question 4 with 1 blank : una persona que va a una fiesta Question 5 with 1 blank : estar juntos para siempre Question 6 with 1 blank : divertirse Question 7 with 1 blank : cuando la persona no sabe lo que va a pasar Question 8 with 1 blank : la relacin entre dos personas que se llevan bien Completar Modelo Marta rompi con su novio. Question 9 with 1 blank Ayer Marta le un reloj a Pablo. Question 10 with 1 blank En el verano, a todos les gusta comer . Question 11 with 1 blank Despus de ser por un ao, Juana y Armando decidieron comprometerse. Question 12 with 1 blank A qu hora van a llegar los a la fiesta del sbado? Question 13 with 1 blank Pablo y Mara se comprometieron antes de . Question 14 with 1 blank Mi sobrina y yo tenemos una buena , somos muy buenas amigas. Question 15 with 1 blank Gabriela no sabe que le vamos a dar una fiesta para su cumpleaos. Question 16 with 1 blank Nosotros lo de vacaciones en Miami. Manuel has recently learned that his favorite grandfather is sick and is going to die within the next six months. Although he is only 7 years of age, Manuel has started displaying some curious symptoms. He has frequent headaches and stomach pains with no physical explanation, he has become unusually moody and irritable, and he has lost interest in his favorite toys, video games, and television programs. Given what is known about the expression of mental illness in the young, what is the likely cause of Manuel's symptoms? workplace communication can suffer when indivduals ABC is a right triangle in which B is a right angle, AB = 1, AC = 2, and BC = sqrt(3).cos C sin A = I think the answer is 3/4, because cos(c) = adj / hypot and sin(a) = opposite / hypotcos(c) = sqrt(3) / 2sin(a) = sqrt(3) / 2which is 3/4 when multiplied. In the STL container list, the functionpop_front does which of the following?a. inserts element at the beginning of the listb. inserts element at the end of the listc. returns the first elementd. removes the last element from the list What is the product?(x - 3)(2x2 5x + 1) In "The Story of an Hour," which cultural norm is the story mainly addressing? We can include following item(s) during configuration itemidentification:a) User Manuals andDocumentationsb) Source Codec) Software RequirementSpecificationsd) All of the above g A ray of light is incident on a flat reflecting surface and is reflected. If the incident ray makes an angle of 28.7 with the normal to the reflecting surface, what angle does the reflected ray make with the normal? WILL BE COOL I U HELP^^ 11 Points!!REGINA. Lola pointed out that we can save money by having the dance at school. We can use that saved money for other parts of the dancelike decorations, refreshments, and entertainment. Yes, Tommy, you wanted to add something?TOMMY. I understand what Lola is saying about saving money with the venue, but we might be able to spend more on the venue and save on the entertainment by hiring students to DJ. I was talking with Trung and Binhtheyre juniors, and they have professional DJ equipment. We can hire them for the night for $500. I did some research, and other DJs in the area typically charge $1,000 to $1,200.REGINA. OK. So Tommy is introducing the idea of saving money by using less expensive student entertainment. How do people feel about this? Could it work?How does the moderator help the group stay on task in this part of the discussion?A) She refers to her agenda to keep the discussion on track.B) She asks questions to get clarification and to elicit additional opinions.C) She reviews and summarizes her notes on the main points of the discussion.D) She uses body language that shows her engagement and displays attentive listening. Which is the correct MLA format for a parenthetical citation for this medicaljournal?Henry, John. "Studies in the impact of cola on student achievement," Medicine1016 (2013): 89-105. Print.A. (Henry, John 89)B. (Medicine 101, Henry)C. (Henry 89)D. (Student Achievement 89) Mike and Veronica are expecting their first child and they are nervous about all of the possible health issues a baby can face. Explain how knowing their family medical history can be useful for Mike and Veronica and their doctors as they prepare for the birth of their child. the graph of g(x), shown below in pink, has the same shape as the graph of f(x)=x^2, shown in gray. which of the following is the equation for g(x) Which substance is less soluble in hot water than in cold water?A KBrB NaNO3C CO2D Naci Protection against illegal searches and seizures is specified by a. the fourth amendment b. the Civil Rights Act c. the Declaration of Independence. d. none of the above. A sequence of numbers a1, a2, a3, . . . is defined as follows: a1 = 3, a2 = 5, and every term in the sequence after a2 is the product of all terms in the sequence preceding it, e.g., a3 = (a1)(a2) and a4 = (a1)(a2)(a3). If an = t and n > 2, what is the value of an+2 in terms of t ?(A) 4t (B) t^2 (C) t^3 (D) t^4 (E) t^8 The Revolutionary War had wrenching effects on the American economy. What eco- nomic problems became especially acute during wartime? How did the states and the Second continental Congress attempt to address them? The expression vecCont.empty() empties the vector container of all elements.TrueFalse