Why are principles, laws and axioms useful in science and engineering?
| a) | Without principles science and engineering can be unethical |
| b) | They provide an overarching understanding that can be applied to a wide variety of problems |
| c) | They make disciplines harder to learn and teach so only top students can master them |
| d) | They recognize and exploit the commonalities in a class of problems and solutions to facilitate finding solutions |
| e) | All of the above |
| f) | a and b only |
| g) | b and d only |
In: Mechanical Engineering
A firm has discovered that its sales are highly correlated to a certain economic parameter. The value for that parameter has been predicted to be 15 for the next year (7th year). Use regression modeling to develop a forecast for the next year.
|
Year |
1 |
2 |
3 |
4 |
5 |
6 |
|
Econ. Parameter |
16.2 |
14.9 |
18.5 |
16.1 |
13.8 |
15.4 |
|
# Sales |
120 |
100 |
165 |
140 |
100 |
110 |
In: Mechanical Engineering
True or False
1. Shafts utilized for constant power transmission with no supported components may be designed using static failure theory.
2. Slope and deflection of shafts are constrained to ensure proper functionality of the supported components
3. For a given bending moment loading and length, a shaft with smaller diameter will result in smaller angular deflection at the bearing supports.
4. For a shaft subjected to combined variable bending and constant torsional loading, the shaft diameter at the critical location can be determined using Gerber theory
5. A shaft that satisfies deflection constraints for a given loading will have an infinite life
6. Langer failure theory best predicts fatigue failure of shafts under variable bending and torsion
7. Material of the shaft is chosen such that strength is greater than applied loading at critical location in order to ensure desired life and meet reliability requirements.
In: Mechanical Engineering
A kanban system has a rate of delivery, which equals the rate of arrival to the system, of 60 batches in a 10-hr day. Each batch contains 8 parts, and the processing time of a batch is exactly 8 minutes. The time between arrivals is known to have the exponential distribution. Compute the proportion of time the system is busy (?), the lead time, and the WIP (in terms of batches).
In: Mechanical Engineering
What is the effect of increasing feed and speed on (i) machining rate and (ii) tool life
In: Mechanical Engineering
Differentiate turning, milling, and drilling in terms of (i) purpose, (ii) feed stock geometry, and (iii) orientation and direction of motion of tool with respect to part.
In: Mechanical Engineering
A continuous evaporator is operated with a given feed material
under conditions in which the
concentration of the product remains constant. The feed rate at the
start of a cycle after the
tubes have been cleaned has been found to be 5000 kg/h. After 48 h
of continuous operation,
tests have shown that the feed rate decreases to 2500 kg/h. The
reduction in capacity is due to
true scale formation. If the downtime per cycle for emptying,
cleaning, and recharging is 6 h,
how long should the evaporator be operated between cleanings in
order to obtain the maximum
amount of product per 30 days?
In: Mechanical Engineering
Get the avehighs.txt file from BB. The file contains monthly average temperatures from three different locations. The location ID is in the first column and monhtly average temperatures are in the next 12 columns. Write a script that will:
data from file
avehighs
432 33 37 42 45 53 72 82 79 66 55 46 41 777 29 33 41 46 52 66 77 88 68 55 48 39 567 55 62 68 72 75 79 83 89 85 80 77 65
1. load the data
2. call a function that will (a) plot the data on a column of subplots (b) place an x label, months, on the last plot (c) place a ylabel,Monthly Avg Temp (F), on the second plot, (d) for a bonus put a legend on each plot that indicates the location id, and (e) return the yearly average temperatures and the location ID as three two element vectors
3. Display the average yearly temp for each location.
In: Mechanical Engineering
I wish to use a B-type thermocouple to measure a temperature of 16000C. I am using 1000C (boiling water) as my reference temperature. What is the emf expected at 16000C ? (Refer to the NIST thermocouple database):
a)
11.233 mv
b.
0.033 mV
c.
11.263 mV
d.
None of the above
In: Mechanical Engineering
A roller bearing has a 22 kN radial load applied. For a life of 18000 hours at 1200 rev/min, specify the smallest suitable roller bearing to use. Assume a rotating outer ring and provide relevant source information for your selected bearing.
In: Mechanical Engineering
Argon gas enters an adiabatic compressor at 16.0 psia with 99 F with a velocity of 49.9 ft/s. It exits at 225 psia and 209.5 ft/s. If the isentropic efficiency of the compressor is 83.1%, determine:
a) the exit temperature (R) of the argon
b) the work input to the compressor (Btu/lbm)
In: Mechanical Engineering
A Rankine cycle with reheat produces 1 MW of net power. The boiler operates at 15 MPa and has an outlet temperature of 800 K. The condenser operates at atmospheric pressure (1 atm). The operating point of this cycle is such that the water exiting the low pressure turbine has no liquid present to prevent damageto the turbine (hint: what does this say about quality at this point?). Assume the pump and second turbine stage are both isentropic, but the first turbine stage has an isentropic efficiency of 90%. Assume the steam is reheated at a pressure of 1 MPa.
Find:
(A)The mass flow rate of steam through the turbines
(B)The required heat input
(C)The required flow rate of fuel given a heating value of 50 MJ/kg
(D)Plot the state points on a T-s diagram with lines of constant pressure at the boiler,reheat, and condenser pressures.
In: Mechanical Engineering
Explain how Doppler (Fuel Temperature Coefficient) changes as fuel temperature rises. Why does this occur? A picture will be helpful.
In: Mechanical Engineering
Show to use ode45 built-in function in MATLAB to solve the following ODE problem:
dydx=x^2 / y y(0)=2
Calculate y(x) for 0 ? x ? 20 and compare the results to analytical solution y = sqrt((2x^3 / 3) + 4)
In: Mechanical Engineering
1. What has the greatest influence on the length and detail of a process plan, and why?
2. What usually determines the way a process plan starts out?
In: Mechanical Engineering