a- Do you consider hardness an important mechanical property? why? (specify few examples).

b- Comprare and distinguish between the Vickers, Brinell, and Rockwell tets.

c- which of the following have the highest hardness and why?

Brass, Mild steel, Aluminum

d-What is the purpose of microscope used in Brinell hardness test?

Explain the ggeometrically necessary dislocation(GND) in comparison with statistically stored dislocation(SSD)

A 3/4" diameter hole is to be drilled through 3/4" thick piece of steel plate. The twist drill is to be fed at 0.025 ipr. Maximum cutting speed of 70 fpm is recommended.

Calculate:

A) Cutting time

B) Metal Removal Rate (MRR)

0.1 kg of air (ideal gas) is contained in a closed, rigid tank of volume 0.04 m^3 at 500 K. A paddle wheel stirs the air and transfers energy to the air at a constant rate of 1 kW for 100s. The temperature of the air increases to 600 K.

(a) What is the final pressure of the air (kPa)

(b)Calculate the heat transfer (kJ) for the process (use a constant, average specific heat)

0.1 kg of air (ideal gas) is contained in a closed, rigid tank of volume 0.04 m^3 at 500 K. A paddle wheel stirs the air and transfers energy to the air at a constant rate of 1 kW for 100s. The temperature of the air increases to 600 K.

(a) What is the final pressure of the air (kPa)

(b)Calculate the heat transfer (kJ) for the process (use a constant, average specific heat)

How to calculate the stiffness of an irregular shaped steel frame ? Include all equations and information needed.

Prove: under the same compression ratio, the thermal efficiency of the Otto cycle is greater than the thermal efficiency of the Diesel cycle?

Helium at 200 kPa, 227 C is expanded in steady flow through a nozzle to 100 kPa. At these operating conditions the nozzle efficiency is 76%.

a) Making the usual nozzle assumptions, calculate the actual velocity at the nozzle exit. Start with the appropriate form of the first law.

b) Calculate the actual nozzle exit temperature.

Superheated steam at 8 MPa and 480°C leaves the steam generator of a vapor power plant. Heat transfer and frictional effects in the line connecting the steam generator and the turbine reduce the pressure and temperature at the turbine inlet to 7.7 MPa and 440°C, respectively. The pressure at the exit of the turbine is 10 kPa, and the turbine operates adiabatically. Liquid leaves the condenser at 8 kPa, 36°C. The pressure is increased to 8.6 MPa across the pump. The turbine and pump isentropic efficiencies are 88%. The mass flow rate of steam is 79.53 kg/s. Determine

(a) the net power output, in kW.
(b) the thermal efficiency.
(c) the rate of heat transfer from the line connecting the steam generator and the turbine, in kW.
(d) the mass flow rate of condenser cooling water, in kg/s, if the cooling water enters at 15°C and exits at 35°C with negligible pressure change.
book used is fundimentails of thermodynamics

OCCUPATION : Production AND industrial  

WHAT ARE THE RESPONSIBILITIES WILL BE IN THE JOB?

WHAT IS MY ANNUAL INCOME WILL BE?

WHAT I HAVE TO DO TO ACCOMPLISHED FINANCIALLY?

.

WHAT I HAVE TO DO TO BROADEN MY MENTAL HORIZONS?

DESCRIBE, IN DETAIL, what should my SYSTEMATIC EDUCATIONAL PLAN FOR ACHIEVING

           what the10 YEAR PROJECTED GOALS (particularly as it relates to items 5 and 6)
                

The water in a 40-L tank is to be heated from 15°C to 45°C by a 25-cm-diameter spherical heater whose surface temperature is maintained at 85°C. Determine how long the heater should be kept on.

Given: The properties of air at 1 atm and the film temperature of 57.5°C.

Fluid temperature = Average temperature for water (15+45)/2=30°C

k = 0.6515 W/m.°C, v = 0.493 x 10^-6 m²/s, Pr = 3.12, and ? = 0.501 x 10^-3 K^-1

The properties of water at 30°C.
? = 996 kg/m³ and c_p = 4178 J/kg.°C, and volume, V = 0.040 m³

Water is used to cool ethylene glycol in a 18.3-m-long double pipe heat exchanger made of 4-std and 2-std (both type M) copper tubing. The water inlet temperature is 15.6°C and the ethylene glycol inlet temperature is 82.2°C. The flow rate of the ethylene glycol is 9.07 kg/s, while that for the water is 13.6 kg/s. Calculate the expected outlet temperature of the ethylene glycol and determine the pressure drop expected for both streams. Assume counterflow, and place the ethylene glycol in the inner tube. Compose a Summary of Performance chart.

A zero-momentum spin stabilized satellite has a momentum wheel spinning at 5000 rpm. The angular momentum of the wheel is 100 N-m-sec.

a) What is the spin rate of the satellite if its moment of inertia is 500 kg-m²?

b) What is the moment of inertial of the wheel?

c) If there were a problem with the wheel and it was stopped, what would be the spin rate of the satellite?

d) Assuming the problem was fixed, how long would it take to get back up to a speed of 4000 rpm applying a motor torque of 0.1 N-m?

e) What would the new spin rate of the satellite be?

For the differential equation x′′ + (o.1)(1 − x2)x′ + x = 0; x(0) = 1, x′(0) = 0. (a) Rewrite it as a system of first order differential equations in preparation to solve with the vectorized version of a numerical approximation technique. (b) Use the vectorized Euler method with h = 0.2 to plot out an approximate solution for t = 0 to t = 10. (c) Plot the points to the approximated solution (make a scatter plot), make a prediction of what type of function the solution might be.

1) Present ten standards compliance certificate for the design of shell and tube heat excanger

2) Present the safety features and considerations that can be adopted for the shell and tube heat heat exchanger

1) Present ten standards compliance certificate for the design of double pipe heat excanger

2) Present the safety features and considerations that can be adopted for the double pipe heat heat exchanger