Microchips found inside most electronic devices today are examples of what material A. Polymers B. Alloys C. Composites D. None of the above. E. Metals

Answer:

To convert a fraction to a decimal, divide the numerator by the denominator.

Answer:

4.83m/[tex]s^{2}[/tex]

Explanation:

For a particle moving in a circular path the resultant  acceleration at any point is the vector sum of radial and the tangential acceleration

Radial acceleration is given by [tex]a_{radial}=w^{2}[/tex]r

Applying values we get  [tex]a_{radial}=(2t)^{2}[/tex]X0.3m

Thus [tex]a_{radial}=1.2t^{2}[/tex]

At time = 2seconds [tex]a_{radial}= 4.8m/s^{2}[/tex]

The tangential acceleration is given by [tex]a_{tangential} =\frac{dV}{dt}=\frac{d(wr)}{dt}[/tex]

[tex]a_{tangential}=\frac{d(2tr)}{dt}[/tex]

[tex]a_{tangential}= 2r[/tex]

[tex]a_{tangential}=0.6m/s^{2}[/tex]

Thus the resultant acceleration is given by

[tex]a_{res} =\sqrt{a_{rad}^{2}+a_{tangential}^{2}}[/tex]

[tex]a_{res} =\sqrt{4.8^{2}+0.6^{2}  } =4.83m/s^{2}[/tex]

Answer:

969.68N

Explanation:

d₁=0.04 m      A₁=[tex]\frac{\pi d^2_{1}  }{4}[/tex]

[tex]A_{1} =\frac{\pi \times .04^2}{4}= 0.00125m^{2} \[/tex]

d₂=0.02 m      A₂=[tex]\frac{\pi d^2_{2}  }{4}[/tex]

[tex]A_{2} =\frac{\pi \times .02^2}{4}= 0.00031m^{2} \[/tex]

Q=1.2m³/min        Q=1.2/60=0.02m³/s

using continuity equation

Q₁=A₁v₁

v₁=Q₁/A₁=0.02/0.00125=16m/s

Q₂=A₂v₂

v₂=Q₂/A₂=0.02/0.00031=64.5m/s

[tex]F_{inlet}=\rho A_{1}v_1^{2}[/tex]

[tex]F_{inlet}=1000\times 0.00125\times16^{2}=320N[/tex]

[tex]F_{outlet}=\rho A_{2}v_2^{2}[/tex]

[tex]F_{outlet}=1000\times 0.00031\times64.5^{2}=1289.68N[/tex]

Force on the nozzle=F_{outlet}-F_{inlet}

= 1289.68-320

=969.68N

Answer:

Answer is c 0.500

Explanation:

[tex]SpecificGravity=\frac{\rho _{fluid}*g}{\rho _{water}*g}[/tex]

We know that [tex]\rho_{water}=62.42lb/ft^{3}[/tex]

Applying values we get

[tex]SpecificGravity=\frac{31.2}{62.4}=0.5[/tex]

Answer:

[tex]\eta[/tex]=0.60

Explanation:

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

      [tex]P_1=100 KPa  ,T_1=300K[/tex]

  [tex]\frac{V_1}{V_2}[/tex]=r ⇒ r=16

As we know that  

   [tex]T_2=T_1(r^{\gamma-1})[/tex]

So [tex]T_2=300\times 16^{\gamma-1}[/tex]

  [tex]T_2[/tex]=909.42K

Now find the cut off ration [tex]\rho[/tex]

      [tex]\rho=\frac{V_3}{V_2}[/tex]  

         [tex]\frac{V_3}{V_2}=\frac{T_3}{T_2}[/tex]

[tex]\rho=\frac{2031}{909.42}[/tex]

 [tex]\rho=2.23[/tex]

So efficiency of diesel engine

[tex]\eta =1-\dfrac{\rho^\gamma-1}{\gamma\times r^{\gamma-1}(\rho-1)}[/tex]

Now by putting the all values

[tex]\eta =1-\dfrac{2.23^{1.4}-1}{1.4\times 16^{1.4-1}(2.23-1)}[/tex]

So [tex]\eta[/tex]=0.60

So the efficiency of diesel engine=0.60

Answer:

A two stroke engine produces twice the power compared to a four stroke engine of same weight and size.

Explanation:

               In a  two stroke engine, all the four processes namely, intake stroke, compression stroke, power stroke and exhaust stroke takes place in one revolution of crankshaft or two strokes of the piston. While in a four stroke engine, all the four processes namely intake stroke, compression stroke, power stroke and exhaust stroke take place in two revolution of crankshaft or four strokes of the piston.

            Therefore, there is one power stroke in one revolutions of the crankshaft in case of a two stroke engine as compared to the four stoke engine where there is one power stroke for two revolutions of the crank shaft.

             So the power developed in a two stroke engine is more ( nearly twice ) as compared to a four stroke engine of the same capacity. When power produced is more, the heat dissipation is also more in case of a two stroke engine. So greater cooling is required to dissipate heat from a two stroke engine as compared to a four stroke engine.

           Also in a two stroke engine, the lubricating oil is used with the oil whereas a four stroke engine has a separate tank for lubricating oil. So the lubricating oil gets burnt quickly in a two stroke engine.

Thus, to dissipate more heat, a two stroke engines has greater cooling and lubrication requirements than a four stroke engines as power produce in a two stroke engine is more than a four stoke engine with same weight or size.

Answer:

55.56%

Explanation:

Given data

Temprature of hot reservior =2000°c=2273k

Temprature of Cold reservior=25°c=298k

Power produced by engine=50MW

Heat rejected =40MW

we know that Effeciency(η) of heat engine=[tex]\frac{Work produced}{heat supplied}[/tex]

Also we know that

heat supplied[tex]\left ({Q_s} \right )=work produced{W}+Heat rejected{Q_r}[/tex]

Q_s=50+40=90MW

η=[tex]\frac{W}{Q_s}[/tex]

η=[tex]\frac{50}{90}[/tex]

η=55.55%

Answer:

Out of the four options provided, the most accurate answer is

option b) increase in the buoyancy force

Explanation:

Natural convection is a process in which thermal expansion of fluid takes place naturally due to natural buoyancy resulting in motion of fluid when it is heated.

Differences in densities result in buoyancy and natural convection depends on buoyancy force. Also higher air temperatures are found at lower densities which is found at the outlets of the channels and the larger the channel size, the larger is the buoyancy force (as the density difference will be higher).

Answer:

b). false

Explanation:

Lean manufacturing

Lean manufacturing, a philosophy developed by Toyota Production System are means to eliminate wastes. They are defined as the techniques or management activities in eliminating wastes and increasing the efficiency inside an organisation.

    According to the concept of lean manufacturing, mainly seven types of wastes are identified. They are :

1. Transportation waste

2. Inventory waste

3. Over production

4. Waiting

5. Defects

6. Motion waste

7. Non utilized talent

All these waste affect greatly to the efficiency of an organisation and devalue its services.  Lean manufacturing advises to prevent  all these waste in order to increase the productivity.

       All the management activities and techniques used in lean manufacturing may be different according to the business application but they are all based on the same basic principle of removing wastes and errors and increase efficiency.

The different sectors that are benefiting from lean manufacturing methodology are

Healthcare

Hospitality

Food and Beverage

Government

Manufacturing

Lean manufacturing can be used in different sectors.

Answer:

x3=0.100167

Explanation:

Let's find the answer.

Because we are going to find the solution for sin(Ф)=0.1 then:

f(x)=sin(Ф)-0.1 and:

f'(x)=cos(Ф)

Because 0<Ф<π/2 let's start with an initial guess of 0.001 (x0), so:

x1=x0-f(x0)/f'(0)

x1=0.001-(sin(0.001)-0.1)/cos(0.001)

x1= 0.100000

x2=0.100000-(sin(0.100000)-0.1)/cos(0.100000)

x2=0.100167

x3=0.100167

Answer:

the heat loss from this insulated wire is less

Explanation:

Given data in question

diameter of cable (d)  =  20 mm

( K ) = 1 W/m-k

heat transfer coefficient (h) = 50 W/m²-K

To find out

the heat loss from this insulated wire

solution

we will find out thickness of wire

heat loss is depend on wire thickness also

we have given dia 20 mm

so radius will be d/2 = 20/ 2 = 10 mm

Now we find the critical thickness i.e.

critical thickness = K / heat transfer coefficient

critical thickness = 1 / 50 = 0.02 m i.e. 20 mm

now we can see that critical thickness is greater than radius 10 mm

so our rate of heat loss will be decreasing

so we can say our correct option is (a) less

Answer:

Heat transfer for a internally reversible process.

Explanation:

Internally reversible means that there is entropy generation ' with in ' the system.

Heat transfer of a process is considered to be reversible if it occurs because of any minute temperature difference between the surrounding and the system .  

Let us consider an example ,  

Transferring of the heat across the difference in  temperature of 0.0001 °C appears as  more reversible than for the difference in temperature of 100 °C .  

Hence ,  

By heating or cooling a system for a number of infinitesimally small steps , we can approximate a reversible process.

Answer: False

Explanation: Sandwich materials are usually in composite material form which has a fabrication of two thin layers which are stiff in nature and have  light weighing and thick core .The construction is based on the ratio that is of stiffness to the weight .Therefore, the density of the material in the core is not high and are only connected with the skin layer through adhesive .So the given statement is false that sandwich materials typically use a high density core with non- structural cover plates.

The mechanical dynamometer is an instrument used to measure forces or to calculate the weight of objects. The traditional dynamometer, invented by Isaac Newton, bases its operation on the stretching of a spring that follows the law of elasticity of Hooke in the measurement range. Like a scale with elastic spring, it is a spring scale, but it should not be confused with a scale of saucers (instrument used to compare masses).

These instruments consist of a spring, generally contained in a cylinder that in turn can be inserted into another cylinder. The device has two hooks or rings, one at each end. The dynamometers have a scale marked on the hollow cylinder that surrounds the spring. When hanging weights or exerting a force on the outer hook, the cursor of that end moves on the external scale, indicating the value of the force.

The dynamometer works thanks to a spring or spiral that has inside, which can be lengthened when a force is applied on it. A point or indicator usually shows, in parallel, the force.

Answer:

Velocity component in x-direction [tex]u=-\frac{3}{2}x^2-\frac{1}{3}x^3[/tex].

Explanation:

   v=3xy+[tex]x^{2}[/tex]y

We know that for incompressible flow

   [tex]\frac{\partial u}{\partial x}+\frac{\partial v}{\partial y}=0[/tex]

[tex]\frac{\partial v}{\partial y}=3x+x^{2}[/tex]

So   [tex]\frac{\partial u}{\partial x}+3x+x^{2}=0[/tex]

[tex]\frac{\partial u}{\partial x}= -3x-x^{2}[/tex]

By integrate with respect to x,we will find

[tex]u=-\frac{3}{2}x^2-\frac{1}{3}x^3[/tex]+C

So the velocity component in x-direction [tex]u=-\frac{3}{2}x^2-\frac{1}{3}x^3[/tex].

Answer:

a.  [tex]\tau=51.55 MPa[/tex]

b.[tex]\tau=42.95MPa[/tex]

c.[tex]\theta=7.67\times 10^{-3}[/tex] rad.

Explanation:

Given: [tex]D_i=350 mm,D_o=420 mm,T=300 KN-m ,G=80 G Pa [/tex]

We know that

[tex]\dfrac{\tau}{J}=\dfrac{T}{r}=\dfrac{G\theta}{L}[/tex]

J for hollow shaft [tex]J=\dfrac{\pi (D_o^4-D_i^4)}{64}[/tex]

(a)

 Maximum shear stress [tex]\tau =\dfrac{16T}{\pi Do^3(1-K^4)}[/tex]

      [tex]K=\dfrac{D_i}{D_o}[/tex]⇒K=0.83

[tex]\tau =\dfrac{16\times 300\times 1000}{\pi\times 0.42^3(1-.88^4)}[/tex]

   [tex]\tau=51.55 MPa[/tex]

(b)

We know that [tex]\tau \alpha r[/tex]

So [tex]\dfrac{\tau_{max}}{\tau}=\dfrac{R_o}{r}[/tex]

[tex]\dfrac{51.55}{\tau}=\dfrac{210}{175}[/tex]

[tex]\tau=42.95MPa[/tex]

(c)

[tex]\dfrac{\tau_{max}}{R_{max}}=\dfrac{G\theta }{L}[/tex]

[tex]\dfrac{51.55}{210}=\dfrac{80\times 10^3\theta }{2500}[/tex]

[tex]\theta=7.67\times 10^{-3}[/tex] rad.

1. Define Viscosity

In physics, Viscosity refers to the level of resistance of a fluid to flow due to internal friction, in other words, viscosity is the result of the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow. For example, the honey is a fluid with high viscosity while the water has low viscosity.

What are the main differences between viscous and inviscid flows?

Viscous flows are flows that has a thick, sticky consistency between solid and liquid, contain and conduct heat, does not have a rest frame mass density and whose motion at a fixed point always remains constant. Inviscid flows, on the other hand, are flows characterized for having zero viscosity (it does not have a thick, sticky consistency), for not containing or conducting heat, for the lack of steady flow and for having a rest frame mass density

Furthermore, viscous flows are much more common than inviscid flows, while this latter is often considered an idealized model since helium is the only fluid that can become inviscid.

Answer:

0

Explanation:

output =transfer function H(s) ×input U(s)

here H(s)=[tex]\frac{s}{(s+3)^2}[/tex]

U(s)=[tex]\frac{1}{s}[/tex] for unit step function

output =H(s)×U(s)

=[tex]\frac{s}{(s+3)^2}[/tex]×[tex]\frac{1}{s}[/tex]

=[tex]\frac{1}{(s+3)^2}[/tex]

taking inverse laplace of output

output=t×[tex]e^{-3t}[/tex]

at t=0 putting the value of t=0 in output

output =0

Answer:

Tolerance is important for the very fact that providing proper tolerances ensures proper fittings of different parts.                                            

Explanation:

Tolerance and dimensioning is an important link between manufacturing and engineering.

Tolerance optimization leads to high cost of machined part to be produced and also provides good quality product. Whereas loose tolerance means reduction in cost but poor quality product. hence it is very important and critical to provide the right tolerance while designing a product.

                               Tolerance also influence what type of production processes to be selected by the process planners. The optimization of the tolerances during the design phase has a positive impact on the results coming out of the manufacturing processes.

                                Providing proper tolerances ensures that the parts will fit properly.

Therefore, providing proper tolerances, the engineers shares the responsibility to manufacture the parts correctly.

Answer:

0.5 feet

Explanation:

it is given that the martin floats at draft of 23'6"

GM=1.5

The load is given as follows

1400 tons is loaded as 2 feet above keel

1400 tons-----kg----2 feet

final kg = [tex]\frac{final moment }{final dispacement}[/tex]

[tex]\frac{weight}{1400 kg}[/tex] =  [tex]\frac{kg}{2 feet}[/tex] =   [tex]\frac{moment of keel }{2800}[/tex]

final kg = [tex]\frac{2800}{1400}[/tex]=2 feet

final GM =2 feet-1.5 feet

=0.5 feet

Answer:  (1) heat power and convection

                (3)radiation

Explanation: Heat can be transferred in many different ways such as conduction,radiation form and convection etc.

Convection is a method of transferring of the heat from a particular surface by the help of fluids .E.g.- air

Radiation is the method of transfer of heat by the emission or absorption process in the other surface.E.g.- earth getting warm due to sun.

Therefore the answer to the question is option (1) and (3).

Answer:  a) The technology that deals with the generation, control and transmission of power using pressurized fluids

Explanation: Fluid power is defined as the fluids which are under pressure and then are used for generation,control and transmit the power. Fluid power systems produces high forces as well as power in small amount . These systems usually tend to have better life if maintained properly. The force that are applied on this system can be monitored by gauges as well as meter.

Answer:

The most common type of pumps are Positive displacement and Non positive displacement pumps.

Explanation:

Pumps are two types:

     (A) Positive displacement pump

             (a)Gear pump

                      (1) Ge rotor pumps

                      (2)Internal gear pumps

                      (3)Lobe pumps

                      (4) External gear pumps

               (b)Piston pump

                       (1)Radial piston

                       (2)Axial piston

               (c)vane pump

        (B) Non positive displacement pump

             (a) Centrifugal pump

Answer:

C) Injection

Explanation:

Injection is a molding process, not a heat transfer mechanism.

Answer:

[tex]V=68.86ft^3[/tex]

Explanation:

[tex]T_1[/tex] =10°C,[tex]T_2[/tex] =93.33°C

Q=500 btu=527.58 KJ

[tex]P_1= 2atm[/tex]

If we assume that air is ideal gas   PV=mRT, ΔU=[tex]mC_v(T_2-T_1)[/tex]

Actually this is closed system so work will be zero.

Now fro first law

Q=ΔU=[tex]mC_v(T_2-T_1)[/tex]+W

⇒Q=[tex]mC_v(T_2-T_1)[/tex]

527.58 =[tex]m\times 0.71(200-50)[/tex]

m=4.9kg

 PV=mRT

[tex]200V=4.9\times 0.287\times (10+273)[/tex]

[tex]V=1.95m^3[/tex]                ([tex]V=1m^3=35.31ft^3[/tex])              

[tex]V=68.86ft^3[/tex]

Answer:

0.1 J/K

Explanation:

entropy change equation is as followed:

[tex]\Delta S=\frac{\Delta Q}{T}[/tex]

where ΔS=entropy change

          Q=Heat transfer

          T= temperature

[tex]\Delta S=\frac{\Delta Q}{T}[/tex]

[tex]\Delta S=\frac{30}{300}[/tex]

[tex]\Delta S=0.1 J/K[/tex]

hence the change in entropy of system which is [tex]\Delta S[/tex]is equal to 0.1 J/K

Answer:

Explanation:

negative feedback control of the amplifier is achieved by applying output voltage signal back to inverting input terminal by feedback

transfer function is T=[tex]\frac{g}{1+Gh}[/tex]

where G=forward Path gain

H=negative feedback gain

here G=[tex]\frac{5}{S+3}[/tex]

H=10

T(S)=[tex]\frac{G}{1+GH}[/tex]

=[tex]\frac{5}{S+53}[/tex]

Answer:500,551.02

Explanation:

Given

Initial enthaly of pump \left ( h_1\right )=500KJ/kg

Final  enthaly of pump \left ( h_2\right )=550KJ/kg

Final  enthaly of pump when efficiency is 100%=[tex]h_2^{'}[/tex]

Now pump efficiency is 98%

[tex]\eta [/tex]=[tex]\frac{h_2-h_1}{h_2^{'}-h_1}[/tex]

0.98=[tex]\frac{550-500}{h_2-500}[/tex]

[tex]h_2=551.02KJ/kg[/tex]

therefore initial and final enthalpy of pump for 100 % efficiency

initial=500KJ/kg

Final=551.02KJ/kg

False it is External

Answer:

True

Explanation:

For point in xz plane the stress tensor is given by[tex]\left[\begin{array}{ccc}Dx_{} &txz\\tzx&Dz\\\end{array}\right][/tex]

where Dx is the direct stress along x ; Dz is direct stress along z ;  tzx and txz are the  shear stress components

We know that the stress tensor matrix is symmetrical which means that tzx = txz  ( obtained by moment equlibrium )

thus we require only 1 independent component of shear stress to define the whole stress tensor at a point in 2D plane