Determine the response of a mass-spring system when it is subjected to a half-sine pulse of 250 dyne amplitude and 0.25? seconds duration. The mass is 20gm and the spring stiffness is 197.4 dynes/cm.

A torsion pendulum with a vanadium wire containing nitrogen, and a period of 2.00 seconds, shows a decrease in the pendulum amplitude, A, of 10 percent in 100 cycles of oscillation at 350K. Compute:

a.The specific damping capacity.

b.The logarithmic decrement.

c. Tan α, where α is the phase angle by which the strain lags the stress.

One kg mole of an ideal gas is compressed isothermally at 127°C from 1 atm to 10 atm in a piston-and-cylinder arrangement. Calculate the entropy change of the gas, the entropy change of the surroundings, and the total energy change resulting from the process, if: (a) the process is mechanically reversible and the surroundings consist of a heat reservoir at 127°C. (b) the process is mechanically reversible and the surroundings consist of a heat reservoir at 27°C. (c) the process is mechanically irreversible, requiring 20% more work than the mechanically reversible compression, and the surroundings consist of a heat reservoir at 27°C.

In sand casting, the volumetric size of the pattern is:

(A) bigger than, (B) same size as, or (C) smaller than the cast part.

Which of the following are advantages of die casting over sand casting (four best answers):

(A) better surface finish,

(B) closer tolerances,

(C) higher melting temperature metals,

(D) higher production rates,

(E) larger parts can be cast, and (F) mold can be reused?

An alloy manufacturer is planning to produce 1000 kg of an alloy with 25% of metal A and 75% of metal B by combining five available alloys. The quantity available and prices for these alloys is shown in the following table. Alloy Type 1 Type 2 Type 3 Type 4 Type 5 %A 10 15 20 30 40 %B 90 85 80 70 60 Available quantity, kg 300 400 200 700 450 Price $/kg 6 10 18 24 30 As the production engineer, you are asked to determine the production schedule that will minimize cost. (a) Clearly formulate the problem giving the objective function and constraints. Clearly show the design variables. (b) Put the problem in standard form. (c) Suggest a method for solving the problem. (d) By hand, solve the problem for the first three tableaus. Adapted from Belegundu and Chandrupatla, Optimization concepts and applications in engineering, Second edition

1. Oil with a specific gravity of 0.75 is pumped by a centrifugal pump at 375 gpm, 19 hp, and 81% efficiency. Determine the pressure head in terms of: a) Feet of oil b) Feet of water

answers: a) 217 ft b) 162 ft

1. A centrifugal water pump impeller is given an inlet and exit radius of 400 mm and 1200 mm, and an inlet and exit blade thickness of 120 mm and 80 mm. The entering and exiting blade angles are 40o and 60o respectively. If the pump rotational speed is 575 rpm with and efficiency of 85%, determine: a) Ideal head (m) b) Fluid power for max pressure (kW) c) Shaft torque for max pressure (Nm)

solutions a) 488 m b) 29,155 kW c) 5.7 x 105 Nm

1.a.Explain how differential action could be prevented.

b.Explain how to achieve reverse direction in Epicyclic Gears.

Water will be pumped from a reservoir free surface of which is at an elevation of “z1” to reservoir the free water surface of which is at “z2”. Both of the reservoirs’ free surfaces at atmospheric pressures.Design a piping system that transmits water from the lower reservoir to the upper reservoir at a volumetric flow rate of Q (m3 /h).

Q = 200 (m3/h) Za = 10(m) Zb= 60 (m) Zc = 75 (m) L1=200 (m) L2=125 (m) "Pipe material is "Commercial Stainless Steel" "

1) Consider necesssary fittings( valves, elbows….)

2) Given data and cost elements, determine the optimum pipe diameter of the system . In order to do this:

3) Write the energy equation between z1 and z2 by taking the major losses associated with the pipe, minor losses associated with the fittings, sudden contraction, and expansion regions inside the system and the pump total head rise ”hp” into account .

4) The average velocity of the water inside your piping system should be between 0.1 and 5 m/s. 5) Calculate the head rise “hp” that must be provided by the pump.

6) Choose a pump that provides a head rise of ”hp” (that you calculated) near its most efficient working flow rate at your given flowrate Q from the local manufacturer’s catalogues.

7) Find the cost of the pipe per one meter (TL/m) and unit electricity price ( TL/kWh). Neglect cost of the pump or pumps.

8) Calculate the cost of the system for one year: Obtain the graph which shows the variation of the capital cost, the energy cost and the total cost in function of the pipe diameter for working of the pump at a rate of 24 hours/day for one year.

9) If head loss from reservoir to pump inlet is 0.8 m, where should the pump inlet be placed to avoid cavitation for water at 15°C, pv= 1.71 kPa absolute?.

10)Check the absolute pressure at point C.

11) Draw a schematic representation of the system.

12) Give necessary technical drawings of the pipe and give schematic representations of the chosen minor loss elements.

13) Give the performance characteristics chart of the chosen pump and the technical drawing of it.

If back rake angle is zero . What will be rake angle

What is back rake angle

A machine cuts N pieces of a pipe. After each cut, each piece of the pipe is weighed and its length is measured. These two values are stored in a matrix called pipe where the first column is the length and the second column is the weight. Each row represents the weight and length of a cut piece of pipe. Ignoring units, the weight is supposed to be between 2.1 and 2.3, inclusive. The length is supposed to be between 10.3 and 10.4, inclusive.

Create a flow chart to do the following, using MATLAB syntax in all blocks:  Count how many rejects there are. A reject is any piece that has an invalid weight and/or length.  Return the number of rejects  Return the percentage of the total number of parts that are rejects

think of three inventions that could not be patented. One due to uselessness, one due to lack of novelity, and one due to being too obvious

Calculate the pressure losses across the different sections of drill pipe and annulus by using the Bingham plastic fluid model (You must draw the wellbore structure chart: without the chart, 50% points will be deducted) PROBLEM: MD/TVD: 12,031 ft Surface casing: 2,135 ft of 133⁄8-in. 61 lb/ft Intermediate casing: 10,786 ft of 95⁄8-in. 40 lb/ft Bit: 85⁄8 in. Nozzles (32nds in.): 11, 11, 11 Surface connections: Case 3 Drill pipe: 41⁄2 in., 16.6 lb/ft Drill collars: 390 ft of 7 in. x 21⁄4 in. Surface pressure: 3,000 psi Mud weight: 12.8 lb/gal Funnel viscosity: 42 sec/qt Plastic viscosity: 19 cP Yield point: 15 lb/100 ft2 Initial gel: 8 lb/100 ft2 Flow rate: 335 gpm

Spacecraft Design Dynamics Conceptual Question:

If I had an oblate spinning spacecraft (hockey puck shaped) spinning about it's z-axis (the body z-axis being normal to the top surface).

If I were to add an internal spinning wheel with that spin axis aligned with the body z (therefore a dual spinner spacecraft) does that change the existing stability at all?

My guess is that it makes it even more stable by adding more resilience to external torque, like a bicycle wheel rotated on its side, internal gyro, etc.