1. If 0.05kg of a gas occupying a volume of 0.03m3 at
1.025 bar is compressed reversibly until the pressure is 6.15 bar.
Calculate the final temperature, the work done on the gas and the
heat flow to or from the cylinder wall when;
a. the process is according to a law PV^1.4=K
b. the process is isothermal
c. the process takes place in a perfectly thermally insulated
cylinder.
In: Mechanical Engineering
-What type(s) of effects are the radiation protection standards trying to prevent?
type the answer please
In: Mechanical Engineering
A certain amount of viscous fluid is placed onto a flat surface. Determine the pi terms that describe the fluid spreading out over the plate as time progresses. For example, these pi terms would describe honey spreading out over a countertop after a drop of it was spilled, or oil spreading on a garage floor after leaking out of a container.
In: Mechanical Engineering
When a safeguard is said to be "muted", what does that means?
In: Mechanical Engineering
Discuss the testing procedures for a fibre composite material, showing all parties involved, from the beginning until obtaining final test report. Discuss also the importance and need of obtaining such test results and not to rely solely on the results of theoretical evaluation. Support your discussion with appropriate literature
In: Mechanical Engineering
Air (cp = 1.0 kJ/kgK) enters an air conditioning system at 40C with a mass flow rate of 1.5 kg/s. The air is cooled by exchanging heat with a stream of R-134a refrigerant that enters the heat exchanger at -8C and 20% quality, and exits with 100% quality. If 25 kW of heat is transferred out of the air, determine: (40 pts) i) Mass flowrate of R-134a (kg/hr) ii) Exit temperature of air (C) iii) Exit pressure of R-134a (kPa)
In: Mechanical Engineering
3. A CNC Lathe is controlled by a 151 step motor which is used to drive a lead screw with 0.25 inch pitch.
(i) What is the precision or minimum distance a carriage on the lead screw can be moved.
4 Decimals, Unit: inch
(ii) To move a distance of 4.5 inches how many pulses are transmitted to the motor.
(iii) If the specification is to move the carriage at the rate of 2.2 inches/minute at what frequency should the pulses be transmitted.
Unit: Hertz
In: Mechanical Engineering
8. Consider an airplane whose takeoff speed is 220 km/h and that takes 15 s to take off at sea level. For an airport at an elevation of 1600 m (such as Denver), determine (a) the takeoff speed, (b) the takeoff time, and (c) the addition al runway length required for this airplane. Assume constant acceleration for both cases.
In: Mechanical Engineering
5
|
P a g e
5.
Define inorganic glass ?
Explain main glass formers, conditional glass formers,
intermediate oxides, and network modifiers? In a viscosity versus temperature profile,
can you please define strain point, annealing point, glass transition temperature, softening
point, and working p
oint
?
In: Mechanical Engineering
5. Consider an airplane with wingspan 40 ft, wing area 250 ft2 , and weight 12,000 lb. Assume that the Oswald efficiency factor is 0.9. The airplane is flying at a velocity of 250 mph at a standard altitude of 5000 ft. Calculate the airplane drag due to lift.
In: Mechanical Engineering
3. A jet aircraft has a drag polar CD = CD,0 + CL 2 /(?e?) = 0.02 + 0.04 CL 2 and wing area 500 m2 . Its initial weight is 3,000,000 N, which includes the fuel weight 1,000,000 N. The thrust specific fuel consumption is 0.9 (N of fuel) / (N of thrust ·hour). Find the maximum endurance of this aircraft.
In: Mechanical Engineering
This is a numerical methods question using MATLAB.
Which of the following code snippets finds the forward difference estimate of the derivative at each of the x values. Assume x and y have been previously defined, for example as
y=[10,20,25, 27.5, 30];
x = [0.3,0.5, 0.8, 0.9, 1];
(d is the derivative variable name)
Although not necessarily so, there may be more than one correct answer.
a) | for k=1:length(y)-1 d(k)=(y(k+1)-y(k))/(x(k+1)-x(k)); end d(k+1)=NaN |
b) | for k=1:length(y) d(k)=(y(k+1)-y(k))/(x(k+1)-x(k)); end |
c) | d(1)=NaN; for k=1:length(y)-1 d(k+1)=(y(k+1)-y(k))/(x(k+1)-x(k)); end |
d) | d(1)=NaN; for k=2:length(y) d(k)=(y(k)-y(k-1))/(x(k)-x(k-1)); end |
In: Mechanical Engineering
A wall is constructed of two layers of 2-cm-thick sheetrock (k = 0.17 W/m·K) separated by 16 cm by wood studs (k = 0.11 W/m·K) whose width is 5 cm. The studs are placed vertically 55 cm apart, and the space between them is filled with stagnant air (16 by 55 cm) as insulation (k = 0.026 W/m·K). Pay attention to the measurements!
The house is maintained at 20°C and the ambient temperature outside is ?9°C. Taking the heat transfer coefficients at the inner and outer surfaces of the house to be 8.3 and 34 W/m2·K, respectively, determine the thermal resistance of the wall in C/W considering arepresentative section (1m x 0.60 m) of the wall to three significant digits. That is from stud end to the other stud end...so a single stud in your section..see plan view below and an example to the right without the sheetrock.
In: Mechanical Engineering
Q] The historical actual sales of an item purchased by a factory is given below. What would have been the forecast had the manager a) used 3 period moving average to make the forecast in the past, and b) used exponential smoothing with alpha=0.2 to make the forecast in the past. Show all calculations. PLEASE PROVIDE TABULATED EXCEL CALCULATIONS.
Month | Actual Sales |
1 | 45 |
2 | 48 |
3 | 37 |
4 | 40 |
5 | 43 |
6 | 37 |
7 | 46 |
8 | 48 |
9 | 42 |
Sub: Material Science
In: Mechanical Engineering
For a bolted assembly with six bolts, the stiffness of each bolt
is kb = 4 Mlbf/in and the stiffness of the members is km = 16
Mlbf/in per bolt. A fluctuating external load applied to the entire
joint cycles between 20,000 lbf and 40,000 lbf. Assume the load is
equally distributed to all the bolts. It has been determined to use
3/8 in - 16 UNC grade 8 bolts with rolled threads. Assume the bolts
are preloaded to 75% of the proof load.
(a) Determine the alternating stress and mean stress carried by a
bolt.
(b) Determine the fatigue factor of safety for infinite life, using
the Goodman criterion and a load line that assumes the preload is
carefully applied and will not vary during operation.
In: Mechanical Engineering