Why is the moment at leading edge(LE)=-c/4 times lift + moment at c/4=-position of center of pressure times lift? The equation shows like this MLE=-c/4*L+Mc/4=-xp*L. Because moment of leading edge and moment at center of pressure or moment at c/4 they always act on the wing but why they equal to each other but not like sum them up? Also, what is neutral point? Is neutral point always change in different situations like flying with different angle of attack? And why the derivative of moment at c/4 of time(d(Mc/4)/dt)=0? Is it because moment at c/4 always constant? Thank you so much

what will be the impact towards society, health,safety and environment if the engineer used diameter of discharge line more than the minimum diameter?

In a pharmaceutical application distilled water with a flow rate of 34560 kg/hr is to cool ethyl alcohol in a parallel flow heat exchanger. The alcohol flowing at 31320 kg/hr enters the exchanger at 75oC and is cooled to 45oC. Assuming that the water flows through the tubes and enters the exchanger at 15oC, determine, for an overall heat transfer coefficient of 0.5kW/m2K the dissipation rate, together with the required heat transfer area. The specific heat capacity of both the alcohol and water is 3.84 and 4.181kJ/kgK

a)

What are the two important physical quantities that characterize wetting and liquid repellency of a

solid surface? Name them, and explain the difference between these two quantities

b)

Peter is playing around with four different solid surfaces (labelled as A, B, C, and D) by placing

different types of liquids onto these surfaces. Peter found something very puzzling: When he

placed small drops of water and oils onto Surface

A, all of these liquids stick to the surfaces.

However, when he placed water and oils droplets onto Surface B, only water can roll off the

surface but oils remain stuck to the surface. Peter

also

found that both water and oils droplets are

highly mobile o

n Surface C, and can be rolled off from the surface. Finally, when Peter placed

both water and oils droplets onto Surface D,

oil droplets are highly mobile but the water droplets

appear to spread completely on the surface. Please provide possible

physical

explanations to all

the above scenarios. Please remember to include schematics and important physical quantities in

your explanations

Describe the procedure to determine the first modal damping. Outline the key steps and sketch the collected acceleration data.

The planet Mars has a diameter of 6772 km, and it orbits the sun at a distance of 227.9 x 10^6 km. If the sun is assumed to radiate like a blackbody at 5760 K, and Mars has an albedo of 0.15 ( reflects 15% of incident radiation back to space), estimate the average temperature of the Martian surface. Ignore the effects of the thin Martian atmosphere.

At steady state, 100 m^3/min of dry air at 32 C, 1 bar is mixed adiabatically with a stream of oxygen at 127 C, 1 bar to form a mixed stream at 47 C, 1 bar. Kinetic and potential energy effects can be ignored.

Find:

(a) the mass flow rates of the dry air and the oxygen

(b) the mole fractions of the dry air and oxygen in the exiting mixture

(c) the time rate of entropy production

Argon gas is initially at a pressure of 10 bar and temperature of 45oC (state 1), while occupying a volume of 0.8 m3 in a frictionless piston-cylinder arrangement. The gas then undergoes a reversible constant volume process to a pressure of 6 bar (state 2), followed by a constant pressure process in which the temperature is restored to 45oC (state 3). a) Sketch the processes on T-s and p-v diagrams b) Assuming perfect gas behaviour determine i) The work done by each process. ii) The heat transfer during each process. iii) The change in entropy in process state 3 to 1. (For Argon take Cp = 519.6 J.kg^-1K^-1 and relative molar mass M=40

compressible flow:

a converging-diverging nozzle has an area ratio of 5 and a stagnation pressure of 1 MPa. Assume that the gas in the nozzle behaves exactly like air. Which of the following most accurately gives the range of nozzle exit pressures for which the flow is choked, but has subsonic flow at the nozzle exit?

a)990 kPa ?? 1 MPa
b)244 kPa ?? 1 MPa
c)21 kPa ?? 1MPa
d)1 kPa ?? 1 MPa
e)244 kPa ?? 990 kPa
f)21 kPa ?? 990 kPa
g)1 kPa ?? 990 kPa
h)21 kPa ?? 244 kPa
i)1 kPa ?? 244 kPa
j)1 kPa ?? 21 kPa

in c++ (Sum, average and product of numbers in a file) Suppose that a text file Exercise13_3.txt contains six integers. Write a program that reads integers from the file and displays their sum, average and product. Integers are separated by blanks.

Instead of displaying the results on the screen, send the results to an output named using your last name.

Example:

      Contents of Exercise13_3.txt:

      Contents of YourLastName.txt:

Run the program for the example above and for another example with 15 scores.

2-) Given the following data:

Drilling Fluid Density : 12 ppg

Well Depth: 10,000 ft.

Drill Bit Nozzle Sizes: 13-13-13

Pump Horsepower: 1800

Pump Volumetric Efficiency: 80%

Maximum Pump Pressure: 4,500 psi

Minimum Flow Rate: 350 gpm

Parasitic pressure losses of 2,173 psi and 1,388 psi are anticipated while circulating mud at flow rates 500 gpm and 390 gpm respectively.

a-) Determine the parasitic pressure losses when the bit hydraulic horsepower is maximum.

b-) Determine the optimum flow rate when the bit hydraulic horsepower is maximum.

c-)Determine the pressure drop across bit nozzles when the bit hydraulic horsepower is maximum.

d-) Determine the optimum sizes of three nozzles to be used for the next bit run using the maximum bit hydraulic horsepower criteria.

Air enters a counterflow heat exchanger operating at steady state at 22°C, 0.1 MPa and exits at 7°C. Refrigerant 134a enters at 0.2 MPa, a quality of 0.33, and a mass flow rate of 30 kg/h. Refrigerant exits at 0°C. There is no significant change in pressure for either stream.

Let T₀ = 22°C, p₀ = 0.1 MPa, and ignore the effects of motion and gravity.
Round your answers to 3 significant digits.

Slab milling is performed on the top surface of a rectangular workpiece that is 12.0 in long by 2.5 in wide by 4.0 in thick. The helical milling cutter, which has a 3.0-in diameter and eight teeth overhangs the width of the part on both sides. Cutting speed = 125 ft/min, feed = 0.006 in/tooth, and depth of cut = 0.300 in. Determine (a) machining time, in min, and

(b) maximum metal removal rate during the cut.

in in3/min

(c) If an additional approach distance of 0.5 in is provided at the beginning of the pass (before cutting begins), and an overtravel distance is provided at the end of the pass equal to the cutter radius plus 0.5 in, what is the duration of the feed motion.

Enter your answer

min

1) In an air-standard Brayton cycle, the air enters the compressor at 0.1 MPa and 15?C. The pressure leaving the compressor is 1.0 MPa, and the maximum temperature in the cycle is 1100?C. Determine The pressure and temperature at each point in the cycle. The compressor work, turbine work, and cycle efficiency. For each control volume analysed, the model is ideal gas with constant specific heat at 300 K, and each process is steady state with no kinetic or potential energy changes.

2) A utility runs a Rankine cycle with a water boiler at 3MPa, and the highest and lowest temperatures of the cycle are 450?C and 45?C, respectively. Find the plant efficiency and the efficiency of a Carnot cycle with the same temperatures.

3) A single stage air compressor running at 80 RPM, compress air from a pressure of 1 bar and temperature of 15oC to a pressure of 5 bar. The clearance volume is 5 % of swept volume which is 0.42 m3 . Assuming that the compression and expansion to follow the law, PV(1.3)= constant. Determine volumetric efficiency, mass of air delivered in kg/sec, exit temperature of air and the power required to drive the compressor in KW.

4) The velocity of steam at inlet to a simple impulse turbine is 1000 m/s, and the nozzle angle is 20o. The blade speed is 400 m/s and the blades are symmetrical. Determine the blade angle if the steam is to enter the blade without shock. If the relative velocity at exit is reduced by friction to 80% of that at inlet, what are then the diagram power and the axial thrust for a mass flow of 0.75 kg/s? Calculate also the diagram efficiency in this case.

5) The nozzle of the impulse stage of a turbine receives steam at 15 bar and 300oC and discharges at 10 bar. The nozzle efficiency is 95% and the nozzle angle is 20 o . The blade speed is that required for maximum work and the inlet angle of the blades is that required for entry of the steam without shock. The blade exit angle is 5o less than the inlet angle. The blade velocity coefficient is 0.9. Calculate for a steam flow of 1350 kg/h: The diagram power; The diagram efficiency.