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Engineering

Consider a person standing in a breezy room at 20°C. Determine the total rate of heat transfer from the person if the exposed surface area and the average outer temperature of the person are 1.6 m2and 29°C, respectively. The convective heat transfer coefficient is 6W/m2-k and the emissivity of the person is 0.95.

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Engineering

Consider a large plane wall of thickness L = 0.3 m, thermal conductivity k = 2.5 W/m · °C, and surface area A = 12 m2. The left side of the wall at x = 0 is subjected to a net heat flux of q0 = 700 W/m2 while the temperature at that surface is measured to be T1 = 80°C. Assuming constant thermal conductivity and no heat generation in the wall, a. Express the differential equation and the boundary conditions for steady onedimensional heat conduction through the wall. b. Obtain a relation for the variation of temperature in the wall by solving the differential equation. c. Evaluate the temperature of the right surface of the wall at x = L.

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Engineering

Give two causes that can result in surface cracking on extruded products.

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Engineering

Two hemispherical shells of inner diameter 1m are joined together with 12 equally spaced bolts. If the interior pressure is raised to 300kPa above atmospheric pressure, determine the tensile force in each bolt.

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Engineering

Observe the following pairs of binary numbers:

00011111 and 00100000

00111111 and 01000000

01111111 and 10000000

Describe the general relationships between these pairs of numbers in terms of:

Decimal values.

Powers of 2.

Number of bits required.

Other relationships ...

These descriptions of relationships should hold for all of these pairs of numbers.

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Engineering

The first electricity producing wind turbine was invented in what year?*

-1776

-1808

-1888

-1978

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Engineering

Main technologies used in atms vending machines game consoles and microwave ovens

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Engineering

Is a reversible heat engine more efficient than an irreversible heat engine when operating between the same two thermal reservoirs?

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Cailyn Mckenzie

Engineering

Natural gas containing a mixture of methane, ethane, propane, and butane is burned in a furnace with excess air. (a) One hundred kmol/h of a gas containing 94.4mole% methane, 3.40% ethane, 0.60% propane, and 0.50% butane is to be burned with 17% excess air. Calculate the required molar ﬂow rate of the air.

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Engineering

What are some common ways of converting fuel to useful energy? Check all that apply.

freezing it

rotating it

burning it

heating it

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Engineering

What steel type and ASTM designation is preferred for W-shapes?

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Engineering

A series circuit consists of a 0.440-H inductor, a 380.0-Ω resistor, a 5.70-μF capacitor, and an ac voltage source of amplitude 250.0 V. Find the rms voltage across the capacitor when the circuit operates at resonance.

A) 106 V

B) 129V

C) 95 V

D) 65 V

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Engineering

Each of these geometric shapes has a different number of sides. Arrange the shapes in order from the shape with the greatest number of sides to the shape with the fewest number of sides. Rank these shapes from greatest to fewest number of sides. To rank items as equivalent, overlap them. triangle, square, rectangle, octagon, hexagon, pentagon

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Zachariah Sullivan

Engineering

Technician A says centering cones are used on hub centric wheels. Technician B says centering cones are

used on lug centric wheels. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and Technician B

D. Neither Technician A nor Technician B

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Engineering

Suppose the measured background level is 5.1 mV. A signal of 20.7 mV is measured at a distance of 29 mm and 15.8 mV is measured at 32.5 mm. Correct the data for background and normalize the data to the maximum value. What is the normalized corrected value at 32.5 mm

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