3. Determine the effective spring constant of the following sandwiches of materials under compressive load (determine the material spring constant only). The material sandwiches are being held in place by a ½-13 UNC bolt, nut, and flat washers on both sides. The first and third materials listed in each sandwich are 0.4” thick and the middle material is 0.04” thick, together making a 0.84” thick sandwich

a. Aluminum, copper-asbestos, steel

b. Steel, copper, steel

c. Steel, rubber, steel

d. Steel, rubber, aluminum

e. Steel, aluminum, steel

A 3/4-6 ACME threaded screw is used to lift a 2 kN load. Note that this has a pitch of 1/6. The mean collar diameter is 4 cm. Find the torque to lift and to lower the load using a ball-bearing thrust washer. What are the efficiencies? Is it self locking? You will need to look up ACME thread size standards online for this problem

In a closed combustion vessel, propane (C3H8) and air are mixed at equivalence ratio of 1.11, temperature of 298 K, and pressure of 1 bar. The mixture is burned to produce solely CO2, CO, H2O, and N2. The heat rejected from the vessel is 820 MJ/kmol of fuel. What are the final temperature and final pressure of the mixture? Since neither O2 nor H2 is present in the burned gas, dissociation can be neglected.

Explain what is Single-Phasing

Particle A (mA = 1 kg) is given initial velocity 10 m/s to the right, while particle B (mB = 1:5 kg) is initially at rest. The coecient of restitution for any impact between A and B is 2/3 while the coecient of restitution for impact of either particle with either wall is 5/6. The particles slide along a smooth horizontal supporting surface. Compute the percentage of the kinetic energy remaining in the system of A and B at the moment just before A impacts the wall on the left for the rst time. (Consider the system to have 100% of its energy at the start.) Neglect all friction.

material science question; Please write down the your observation of tearing a plastic bag in a (1) slow and (2) fast fashion, especially any difference in terms of morphology or crack formation!

what are the benefits and disadvantages of a Dynamic Absorber.

Design a gas power plant that works as a non-ideal Regenerative Brayton cycle by determining the pressure ratio required to optimize the net power output of the cycle. The minimum cycle temperature is 300 K while the maximum cycle temperature is 1780 K. The isentropic efficiency of the turbine is 85% while that of the compressor is 75%. The effectiveness of the regenerator is to be taken as 0.8 while the gas flow rate is 30 kg/s. A T-s diagram for the cycle should be provided along with a table showing the pressure and temperature of all the states at the optimized point. Also, mention the cycle efficiency as well as the rate of heat addition and rejection at the optimized point taking the working fluid to be (i) air, and (ii) helium. Ignore pressure drops in the heat exchangers and assume constant specific heats at room temperature

note: i need solution with ees program (detailed information)

List and discuss different robotic applications.

How many constant volume processes are modeled when analyzing an Air Standard Diesel cycle?

Question 10 options:

In a gas turbine plant, air is compressed from 1.01 bar and 15 ?C through a pressure ratio of 4. It is then heated to 650 ?C in a combustion chamber, and expanded back to atmospheric pressure. Calculate the cycle efficiency and work ratio if a perfect heat exchanger is employed. The isentropic efficiencies of the turbine and compressor are 0.85 and 0.80, respectively. ANSWER (0.319, 0.319)

A gas turbine plant consists of a compressor with a pressure ratio of 10, a combustion chamber, and a turbine mounted on the same shaft as the compressor; the net electrical power of the unit is 20 MW. The inlet air conditions are 1.013 bar and 15 ?C and the maximum cycle temperature is 1100 K. The exhaust gases from the turbine are passed through a heat exchanger to heat water for space heating before passing to the chimney; by this means water at 60 ?C flowing at a rate of 2×106 kg/h is heated to 80 ?C. Using the further data below and neglecting the mass flow rate of fuel, calculate; (i) the temperature of the gases leaving the turbine;

(ii) the mass flow rate of air entering the unit;

(iii) the temperature of the gases entering the chimney;

(iv) the overall efficiency of the system defined as the useful energy output divided by the energy input from the fuel. Combined mechanical and electrical efficiency of gas turbine unit, 90 %; combustion efficiency, 99 %; isentropic efficiency of air compressor, 80 %; isentropic efficiency of gas turbine, 83 %; pressure drop in combustion chamber, 0.20 bar; pressure drop of gases in heat exchanger, 0.15 bar; pressure drop in chimney, 0.05 bar; specific heat capacity and ? of combustion gases, 1.15 kJ/kg K and 4/3; mean specific heat capacity of water, 4.191 kJ/kg K.

ANSWER (453.8 ?C; 240 kg/s; 285 ?C; 50 %)

What is a unit step function?

Is the value U(0) = 1?

Ex. when t=20 and equate to U(t-20)=U(0)=1???

. In a gas turbine plant, air enters a compressor at atmospheric conditions of 15 ?C, 1.0133 bar and is compressed through a pressure ratio of 10. The air leaving the compressor passes through a heat exchanger before entering the combustion chamber. The hot gases leave the combustion chamber at 800 ?C and expand through an HP turbine which drives the compressor. On leaving the HP turbine the gases pass through a reheat combustion chamber which raises the temperature of the gases to 800 ?C before they expand through the power turbine, and hence to the heat exchanger where they flow in counter-flow to the air leaving the compressor. Using the data below, neglecting the mass flow rate of fuel and changes of velocity throughout,

calculate: (i) The airflow rate required for a net power output of 10 MW;

(ii) The work ratio of the cycle;

(iii) The temperature of the air entering the first combustion chamber;

(iv) The overall cycle efficiency.

Data: Isentropic efficiency of compressor, 80 %; isentropic efficiencies of HP and power turbine, 87 and 85 %; mechanical efficiency of HP turbine-compressor drive, 92 %; mechanical efficiency of power turbine drive, 94 %; thermal ratio of heat exchanger, 0.75; pressure drop on air side of heat exchanger, 0.125 bar; pressure drop in first combustion chamber, 0.100 bar; pressure drop in reheat combustion chamber, 0.080 bar; pressure drop on gas side of heat exchanger, 0.100 bar.

ANSWERS(91.0 kg/s; 0.25; 611 ?C; 18.9 %)

why is the linear coefficient of thermal expansion in polymers greater than that of ceramic?