Why do the cast iron, carbon steel, and the tempered steel have different behavious about tensile stress-strain, and how would that be different?

I designed a substrate holder for a thermal evaporator for a lab I work in, based on the size of our chamber. It is height adjustable (rod stopping height from falling) with 2 or 3 mm tolerances.

The boat will be very close to tungsten boats as they are heating up. My question is...

what materials should I consider using for this design? And what temperatures can these materials go up to without oxidation occuring? What temperatures can they go up to without melting or significantly deforming?

At the beginning of the compression process of an air-standard Otto cycle, p1 = 1 bar and T1 = 300 K. The compression ratio is 3.5 and the heat addition per unit mass of air is 1400 kJ/kg. Determine: (a) the maximum temperature of the cycle, in K. (b) the net work, in kJ/kg. (c) the percent thermal efficiency of the cycle. (d) the mean effective pressure, in kPa.

True or false: If an ideal gas is throttled in a gate valve from a higher pressure P1 to a lower pressure P2, then the exit temperature T2 is higher than the inlet temperature T1. Why?

Two wisp steel wool hangs in an old fashioned weight. The quantities are adjusted so they weigh exactly the same. The one up is now heated, well with a gas flame, which is then removed.

- What happens?

- Which of the totes is now the heaviest?

- Explain the transformation in the 17th century language.

- Explain the transformation with a modern reaction scheme.

For the questions below, answer if the statement is true or false and explain how you reach to your conclusion.

a. The Clausius statement of the second law denies the possibility of transferring energy by heat from a cooler to a hotter body?

b. The COP if a reversible refrigeration cycles is always equal to the COP of an irreversible refrigeration cycle when each operates between the same two thermal reservoirs.

c. The Kelvin–Planck and Clausius statements of the second law of thermodynamics are equivalent because a violation of one statement implies the violation of the other.

d. Mass, energy, entropy, and temperature are examples of extensive properties.

e. For reversible refrigeration and heat pump cycles operating between the same hot and cold reservoirs, the relation between their coefficients of performance is COPR = COPHP + 1.

f. For a reversible heat pump that operates between cold and hot thermal reservoirs at 300°C and 500°C, respectively, the COP is equal to 2.87

g. An experimentalist claims to have raised the temperature of a small amount of water by 150°C by transferring heat from high-pressure steam at 120°C. Is this a reasonable claim? Assume that no refrigerator or heat pump is used in the process.

h. In the absence of any friction and other irreversibilities, can a heat engine have an efficiency of 100%?

i. A heat pump that is used to heat a house has a COP of 2.5 and delivers 2.5 kJ/s to the house for each 1 kWh of electricity it consumes. Is this a violation of the first law of thermodynamics?

j. You visit a department store interested in buying a AC unit that has a COP of at least 4. The manufacturer labels do not show COP values but shows that the EER for the refrigerator you are interested in is 14. Will this refrigerator meet your COP constraint?

The factorial of an integer ? is defined using the following equation: ?! = ? ∗ (? − 1) ∗ (? − 2) ∗ … ∗ 2 ∗ 1 In combinatorics, permutations is the number of ways of selecting a subset of some elements such that the order matters. For example, there are 6 permutations of letters A, B, and C. A B C ,A C B, B A C, B C A, C A B, C B A, The permutation of selecting ? elements from a set of ? elements can be calculated using the following equation: ?(?, ?) = ?! (? − ?)! On the other hand, combinations is the number of ways of selecting a subset of some elements such that the order does not matter. The combination of selecting elements from a set of m elements can be calculated using the following equation: ?(?, ?) = ( ? ? ) = ?! ?! (? − ?)! Instructions Add a section / cell in your MATLAB m-file script for problem 3 that: • Prompts the user to enter integer ? between 2 and 12 (inclusive) o If the input is invalid, displays an error message and prompt the user to try again, as many times as necessary (use a loop to accomplish this instead of terminating the program) • Prompts the user to enter integer ? between 2 and ? (inclusive) o If the input is invalid, displays an error message and prompt the user to try again, as many times as necessary (use a loop to accomplish this instead of terminating the program) • Determines and displays the following: o ?! o ?(?, ?) o ?(?, ?) This program must use loops to calculate the results – DO NOT use any pre-defined MATLAB functions related to factorials, permutations, and/or combinations.

Five common welding methods are: oxy-acetylene gas welding; tungsten-inert-gas (“TIG”) welding; metal-inert-gas (“MIG”) welding; resistance spot welding; and laser welding. Of these five methods, which are applicable to carbon steels and which to wrought aluminum alloys? Discuss.

At steady state, air at 200 kPa, 330 K, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. The inlet cross-sectional area is 6 cm². At the duct exit, the pressure of the air is 100 kPa and the velocity is 250 m/s.


Neglecting potential energy effects and modeling air as an ideal gas with constant c_p = 1.008 kJ/kg · K, determine:

(a) the velocity of the air at the inlet, in m/s.

(b) the temperature of the air at the exit, in K.

(c) the exit cross-sectional area, in cm².

If you are operating at 1000 knots and altitudes of 60,000 feet, what type of propulsion system should you use?​

The velocity profile for a steady laminar flow in a circular pipe of radius R is given by u=u0(1−r2R2) . If the fluid density varies with radial distance r from the centerline as ρ=ρ0(1+rR)14 , where ρ₀ is the fluid density at the pipe center, obtain and choose the correct relation for the bulk fluid density in the tube.

A) What is the specific internal energy of water at 50 kPa and 190°C? Use data from the steam tables. The specific internal energy of water is ___ kJ/kg.

B) What is the specific volume of R-134a at 20°C and 730 kPa? What is the internal energy at that state? Use data from the steam tables.

The specific volume is ___m3/kg.

The internal energy is ___kJ/kg.

for loop practice – Taylor Series!The moment you finish implementing the trigonometric functions, you realize that you have forgotten your favorite function: the exponential! The Taylor Series for the exponential function is 푒푥=1+푥1!+푥22!+푥33!+...,‒∞<푥<∞a) Using a for loop, compute and display the error of the Taylor series when using 12 and 15 terms, each as compared to the exponential function when evaluated at x = 2. b) Can you figure out how to compute and display the number of terms necessary for this function to have an error within your allowed range of 0.001 when evaluated at x = 3. Display this error. For MATLAB

A 9-cm-diameter vertical water jet is injected upward by a nozzle at a speed of 15 m/s. Determine the maximum weight of a flat plate that can be supported by this water jet at a height of 2 m from the nozzle. Take the density of water to be 1000 kg/m3. The maximum weight of a flat plate that can be supported by the water jet is ____ N

(a) Briefly describe the usefulness of the knowledge of Mechanical Vibration in the industries by discussing at least two examples with regards to effects of machinery vibrations and reduction/control.

(b) Briefly explain the following terms: i. Modal analysis ii. Modal parameters

(c) Briefly explain resonance.

(d) Briefly explain how measurement and monitoring of machine vibration can be used for preventive maintenance.

in short pls