AT mechanics of material,
Can you explain why the contact point between chip( or work) and cutting tool is larger when the cutting speed is slow? I'm very pleased if you explain this to me by using picture or drawing.

You are heating airflow in a long, round tube. The tube is irradiated uniformly, on all sides, with a constant thermal heat flux q". Inside the tube, the air flows with a known heat flux mdot and constant, known properties. The tube has a length L and a diameter D. This is your baseline case. You then add a helical coil inside the tube that stirs up the airflow and doubles the value of h over the baseline case. a) How does the design change impact the temperature of the airflow? b) How does the design change impact the temperature of the tube wall

Explain the significance of the following in a TCP segment:

1) sequence number

2)Acknowledgement number

3) Window

4) SYN Flag

5) FIN Flag

A volume of 8.62 m3 of air in a rigid, insulated container fitted with a paddle wheel is initially at 322 K, 0.4 bar. The air receives 481 kJ by work from the paddle wheel. Assuming the ideal gas model with cv = 0.71 kJ/kg • K, determine for the air the amount of entropy produced, in kJ/K.

A steam thermoelectric plant operates a Rankine cycle with overheating. Water enters the pump as saturated liquid , 7.7 kg/s. The efficiency of the pump is 0.9 The water enters the high pression turbine at 12 500 kPa and 550°C, after that steam overheats at a constant pressure of 2000 kPa until 450°C before it expands on the low pressure turbine. The efficiency of both turbines is 0.85. The vapor quality when it enters to the condenser is 0.95 Determine the thermal efficiency of the cycle.

Is the thrust generated typical of a small jet aircraft engine?

I got -99 N

explain and give me a source

Using Ees Program (With the Code and Output)

Saturated liquid Propane flows in to a valve. It enters at 375 psia, and leaves at 15 psia. Mass flow through the valve is 1.25 lbm/hr. Use EES and ‘Propane’ as your fluid to calculate the following:

The quality of the Propane exiting the valve

Temperature of the Propane exiting the valve (in °F)

The change in entropy of the Propane (in Btu/lbm-R)

a.__________________ b.____________________ c.____________________

1.Humid air at 50 ºC and 1.0 atm with 2 ºC of superheat is fed to the condenser. Gas and liquid streams leave the condenser in equilibrium at 20 ºC and 1 atm.

(a)Assume a basis of calculation of 100 mol inlet air, draw and label a flow chart for the process.

(b)Calculate the mass of water condensed per m3 of air fed and kJ transferred per m3 air fed.

(c)What cooling rate (kW) would be required to process 250 m³ air fed/h?

A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 20%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space.

Introduction to engineering experimentation

A strain sensor manufacturing company tested the average lifetime of their sensor and found the following results in days

1820, 1960, 2050, 1800, 1500, 1750, 1700, 1775, 2000, 1905

a) Find the mean, median, and standard deviation of the lifetime of the sensor

mean= 1826

median=1810

standard deviation=153.6

b) State the type of distribution you would use to estimate the 95% confidence interval on the mean and then calculate the value?

c) Determine if you can reject any of the samples

Consider the design of an engine for a high-efficiency automobile engine design that is to work in conjunction with an electric motor in a hybrid drive. Management wants to know what would be the displacement and efficiency of an engine producing 50 hp (net). Since engines are always rated at ISO (sea level) conditions where their performance is best, take the inlet air to be at 14.7 psia and 59°F. Consider two different directions the company could take:

a) Otto Cycle (four-stroke): In order to convince customers that fuel costs will be low, the sales department recommends that a gasoline engine should use regular-octane fuel, which will limit the maximum CR to 9. The manufacturing engineers have suggested an aluminum alloy that they would like to use in building the engine block and heads, and the strength of this alloy will limit maximum cylinder pressures to 1000 psia. A peak engine speed of 8000 RPM is feasible for this small gasoline engine.

b) Diesel Cycle: Assume a compression ratio of 20 is feasible. Lower cutoff ratios are preferable, and you should design for a value of 1.3 based on the company’s experience with other Diesel engine designs. Maximum engine speeds are typically lower for Diesel engines – assume that 3500 RPM is the upper limit here. For simplicity, assume specific heats can be assumed constant, and take cp=0.24 Btu/lbm-R, cv=0.17 Btu/lbm-R, and k=1.4 throughout both calculations.

After modeling the two cycles, generate a table that compares the two cycles – the table should include (in the following order please) the maximum cycle pressure (in psia), maximum cycle temperature (in °F), volumetric flow rate into the engine (in CFM = cubic feet/min), engine displacement (in liters), and thermal efficiency. Finally, summarize in one or two sentences the primary trade-offs (from your tabular summary) that will dictate the final design choice.

A vehicle burns 150 mole/h of gasoline (C8H18) with 12% excess air in a combustion chamber with 90% fuel conversion.

a) What is the molar flow of incoming air to the combustion chamber? (mol/h)

b) What are the mass flows of the combustion products at the chamber’s exit? (g/h)

Problem 6.082 SI

Steam undergoes an isentropic compression in an insulated piston–cylinder assembly from an initial state where T₁ = 120°C, p₁ = 1 bar to a final state where the pressure p₂ = 50 bar.


Determine the final temperature, in °C, and the work, in kJ per kg of steam.

can anyone exolain to me what is the uses and applictions of (Optical Metamaterials)

please write clear

A thin plate is initially at a uniform temperature of 200°C. At a certain timet = 0 the temperature of the east side of the plate is suddenly reduced to 0°C. The other surface is insulated. Use the explicit finite volume method in con- junction with a suitable time step size to calculate the transient temperature distribution of the slab and compare it with the analytical solution at time (i) t = 40 s, (ii) t = 80 s and (iii) t = 120 s. Recalculate the numerical solution using a time step size equal to the limit given by (8.13) for t = 40 s and com- pare the results with the analytical solution. The data are: plate thicknessL = 2 cm, thermal conductivity k = 10 W/m.K and ?c = 10 × 106 J/m3.K.