A piece of aluminum weighing 6 kg and initially at a temperature of 300◦C is suddenly immersed in a fluid at 20◦C. The convection heat-transfer coefficient is 58W/m2 · ◦C.Taking the aluminum as a sphere having the same weight as that given, estimate the time required to cool the aluminum to 90◦C, using the lumped-capacity method of analysis.

Q: Air cools the top and bottom of an electronic chip that uniformly generates heat. At steady-state,…

A: It is given that air cools the top and bottom of the electronic chip. The chip is subjected to…

Q: Steel pipe (outer diameter 100 mm) is covered with two layers of insulation. The inner layer, 40 mm…

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Q: Unit of convection heat transfer coefficient is, 1. W/m2k 2. W/mk 3. j/mk 4. None of the above

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A: Given that, Given that, The inner diameter of the pipe Di = 12.7 cm = 0.127 m The thickness of the…

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Q: Steam at 140 ° C flows in a pipe having an inner radius of 45 mm and an outer radius of 55 mm. The…

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A: Given data are as follows: Area of wall = 16.2 m2. Convective heat transfer coefficient h = 7W/m2-K…

Q: Problem 5: The energy lost from a 10 cm thick slab of steel is 50 W. Assuming the temperature…

A: Thick Ness of slab t = 10 cm                                  = 0.1 mThermal conductivity k = 45 W/…

Q: A loaf of bread having a surface temperature of 373 K is being baked in an oven whose walls and the…

A: given Temperature of body Tb=373 K Temperature of the surrounding Ts=477.4 K Emissivity e=0.85…

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A: Given, T3=95oC,T2=62oC,T1=35oC,∆x=0.025 m Assume Linear variation of thermal conductivity,…

Q: For the plane wall shown, solve the conduction equation, deriving an algebraic expression for the…

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Q: A round tube (ID = 60mm, OD = 80mm) carrying liquid ammonia has a constant surface temperature of…

A: Given, Density of air, ρ = 1.225 kg/m3 Inner diameter of the insulation, D = 80 mm +2×8 mm= 96×1…

Q: b) A heated sphere of radius R is placed in a large amount of stagnant fluid. Consider the heat…

A: Given:The temperature at the share is constant,So, at r=R, T=TR, and throughout the liquid it…

Q: A rubber insulated copper wire 2 mm diameter is carrying electric current and exposed to a uniform…

A: Given: The diameter of pipe is d = 2 mm = 0.002 m Insulation thickness t = 1 mm = 0.001 m, Consider…

Q: . A glass window of width W = 1 m and height H = 2 m is 5 mm thick and has a thermal conductivity of…

A: Given,the width of the glass window is, The height of the glass window is, The thickness of the…

Q: A metallic sphere of radius R is heated in an oven to a temperature of 600 ° F throughout, and then…

A: Given that the hot metal ball is allowed to cool in ambient air. We need to find the differential…