In a ball bearing production facility, steel balls (k=50 W/m.K, c=0.460 kJ/kg.K, ρ=7865 kg/m3) that are each of 13,99 mm in diameter are annealed by first heating them to 870 oC and then slowly cooling in air to 125 oC. If the cooling air stream temperature is 60 oC, and it has a convective heat transfer coefficient of 35 W/m2.K), determine the time [s] required for the cooling.

Q: OA l-m long hollow cylinder of inner radius 5 cm and outer radius 15 cm is considered. The inner…

A: Given data: The length of the cylinder, L = 1 m. The inner radius of the cylinder, ri = 5 cm. The…

Q: 42 oC with convection heat transfer coefficient of 9.0 W/m2 K. Solar radiation incident on the…

A: given:T0=45CT∞=42C h=9w/m2kthickness l=25cm

Q: What does the lumped capacity model describe? Give an example (with a drawing) of a heat transfer…

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Q: 3. A 2-mm-diameter and 10-m-long electric wire is tightly wrapped with a 1-mm-thick plastic cover…

A: Data given -

Q: Layers of 6-in-thick meat slabs (k = 0.26 Btu/h·ft·°F and a = 1.4 * 1026 ft2/s) initially at a…

A: Given data: Thermal conductivity of metal slab, K= 0.26 Btu/h.ft.0F Thermal diffusivity of metal…

Q: An 8-cm-diameter potato (p = 1100 kg/m2, C, = 3900 J/kg °C, k = 0.6 %3D W/m °C, and a = 1.4 x 10-7…

A: Given data as per the question Diameter of potato =8 cm Initial temperature =250 c The temperature…

Q: Steam exiting the turbine of a steam power plant at 40°C is to be condensed in a large condenser by…

A: Consider below image for cross section across copper tube,   From the data given in question, T2 =…

Q: An exothermic chemical reaction takes place in a 20 cm thick slab and the energy generation rate per…

A: To Find : The heat transfer rate to the surrounding from the right hand side of the slab,Given : The…

Q: A 50-kg box of beef at 8 C having a water content of 72 percent is to be frozen to a temperature of…

A: Assumptions: The beef is at uniform temperatures at the beginning and at the end of the process.…

Q: A short brass cylinder (8530 kg/m3,Cp = 0.389 kJ/kg · °C, k =110 W/m · °C, and α= 3.39 x 10-5 m2/s)…

A: Given, Diameter of cylinder, D = 8 cm Height of cylinder, L = 15 cm Initial temperature of cylinder,…

Q: A 0.025-mm-diameter stainless steel wire having k = 16W / m . °C is connected to two electrodes. The…

A: Given data: It is assumed that the wire is divided into two parts and the section of the separation…

Q: A self-supported steel plate of 8 cm thickness and an initial temperature of 20°C passes through a…

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Q: convection between the hood and the surroundings at. To=27°C,h -T₁, e=0.93 Determine the net rate of…

A: Calculating the net rate of heat transfer between the grill hood and the surrounding by convection…

Q: Q5. A long copper rod of diameter 2.0 cm is initially at a uniform temperature of 100 C. It is now…

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Q: Stainless steel ball bearings (p=8085 kg/m², k=15.1 W/m°C, and C=0.480 kJ/kg.°C) having diameter of…

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Q: Example 2: The roof of an electrically heated home is 6 m long, 8 m wide, and 0.25 m thick, and is…

A:

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.