Mechanical Engineering Answers

Internal energy of certain thermodynamic system is given by 𝑢 = 25 + 0.25𝑇 where T

is temperature in ℃. When the system execute a process, work done per degree

temperature change is given by 𝑑𝑊

𝑑𝑇

= 350√𝑇 N-m, find the heat transferred when the

temperature changes from 100℃ 𝑡𝑜 200℃.

6. A throttling calorimeter is connected to the superheated steam line supplying steam to the auxiliary feed pump on a ship. The line pressure measures 2.5 Mpa. The calorimeter pressure is 110 kpa and 150oC. Determine the entropy of the steam line. Please detailed the solution and answer.

2. Two pulleys 10 in. diameter and 25 in. diameter is connected by an open belt with center distance of 40 in. Find the belt length needed to connect them.

Please answer with detailed solution.

The link lengths for the four-bar linkage are given in the figure. In the

position shown, coupler link 2 is subjected to force F₂ of magnitude

47 N at an angle of 132⁰, and follower link 3 is subjected to force F₃

of magnitude 30 N at an angle of 128⁰. Determine the shaft torque T₁

on input link I and the bearing loads for static equilibrium.

GIVEN:

l₁=30mm; l₂=100mm; l₃=50mm.

"\\phi1 = 135 degree , \\phi2=17 degree, \\phi3=85 degree\n."

r₁=0, r₂=45mm, r₃=38mm.

O₁O₃ = 70mm, O₁B=30mm, BC=100mm, O₃B=50mm.

(Answer ASAP. I wish I could attach the figure!)

Twenty Post-Practical Questions - SSl Time Response [20]

1) Derive the equation for the unit step response of a first order low-pass system.

2) Derive the equation for the unit step response of a second order low-pass system.

3) Explain how you would measure the time constant of a first order system.

4) Explain how you would find the steady state gain of a first order system from the differential equation and by measurement.

5) Derive the formulas for time to peak and % overshoot of an underdamped second order system.

6) Explain how you would measure the damping ratio of a second order system.

7) Explain how you would set initial condition in Matlab Simulink.

8) Explain the pin-out of a μ741 op amp.

9) Why can a μ741 be regarded as having infinite gain?

10) Why can a μ741 be regarded as having infinite input resistance.

5. Two shafts 30 in. apart, each carrying a four-step pulley, are to be connected by a cross belt. The driving shaft is to turn 180 rpm while the driven shaft is to turn 50, 150, 250, and 600 rpm. The smallest step of the driver is 10 in. in diameter. Find (a) the diameters of all the steps, (b) angle of contact for each pair of pulleys, and (c) belt length. Please explain the solution/answer.

Find the directional derivative of fei ( x y z ) =xy^2+yz^3 at ( 2,1,-1) in the direction of i +2j +2k

P500,000 was deposited at an interest of 6% compounded quarterly. Compute the compound interest after 4 years and 9 months.

Answer: P163,475.37

10. A supercritical power generates steam at 25 Mpa and 560􀔨. The condenser pressure is 7 kpa. Determine the exit quality of steam if it expands through a turbine in this power plant.

Answer:

a. 45.66% c. 56.66%

b. 68.45% d. 74.26%

A solid square rod is cantilevered at one end. The rod is 0.6 m long and supports a completely reversing transverse load at the other end of ±2 kN. The material is AISI 1080 hot-rolled steel. If the rod must support this load for 104 cycles with a factor of safety of 1.5 at 100°C, what dimension should the square cross section have? Neglect any stress concentrations at the support end.