Concept explainers
In a cylindrical pipe where area isn’t constant. Equation 16.5 takes the form H = −kA(dT/dr), where r is the radial coordinate measured from the pipe axis. Use this equation to show that the heat-loss rate from a cylindrical pipe of radius R1 and length L is
where the pipe is surrounded by insulation of outer radius R2 and thermal
Figure 16.16 Problem 76
Want to see the full answer?
Check out a sample textbook solutionChapter 16 Solutions
Essential University Physics: Volume 1 (3rd Edition)
Additional Science Textbook Solutions
College Physics: A Strategic Approach (3rd Edition)
Modern Physics
University Physics (14th Edition)
Essential University Physics (3rd Edition)
The Cosmic Perspective (8th Edition)
Sears And Zemansky's University Physics With Modern Physics
- At 25.0 m below the surface of the sea, where the temperature is 5.00C, a diver exhales an air bubble having a volume of 1.00 cm3. If the surface temperature of the sea is 20.0C, what is the volume of the bubble just before it breaks the surface?arrow_forwardAn electronics device generates 30.5 W of heat energy during normal operation. The heat is dissipated from the top surface of the device to ambient air at 23°C. If the top surface area is 0.158 m2 and the convection heat transfer coefficient is 7.838 W/m2. K, what will be the surface temperature (in °C) of the device [round your final answer to one decimal place]? Air, T. T 00 Sarrow_forwardWhat is the rate of heat transfer in J/s through the body's skin and the fat layer just beneath its surface? Treat the skin and fat as a single layer that is 1.20 cm thick. Assume the temperature of the inner surface of the layer corresponds to internal body temperature, or 36.7 °C, and the temperature of the outer surface of the layer corresponds to skin temperature, or 34.0 °C. Take the total surface area of the layer to be 1.50 m² and use a value of 0.413 W/(m-C°) for the average thermal conductivity of the layer. Number Unitsarrow_forward
- Jane's surface area is approximately 1.63 m2 . At what rate H is heat released from her body when the temperature difference across her skin is 2.90∘C? Assume the average thickness of her skin is 1.32 mm, and that skin conducts heat at the same rate as human fat. Provide an answer with two significant figures.arrow_forwardA hot steel plate with a surface area of 1.52 m2 and a constant surface temperature of 166°C is exposed to ambient air at 22°C. If the convection heat transfer coefficient is 15.9 W/m². K, what is the rate of heat transfer (in W) from the plate to the air [round your final answer to zero decimal places]? T. S Air, T, 00arrow_forwardQ8: 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 qo= 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 one-dimensional heat conduction through the wall, (b) obtain a relation for the variation of temperature in the wall by solving the differential equation, and (c) evaluate the temperature of the right surface of the wall at x = L. Answer: (c) -4°Carrow_forward
- A 900 g copper rod at 20 degrees celcius has a length of 1.0000 m. The thermal expansion coefficient of copper is 17 x 10^-6 degrees celcius -1. The specific heat capacity is 0.385 kJ/kg degrees celcius. Question A: The copper is heated to 400 degrees celcius. What is the new length? Give the answer in meters and with 4 digits of precision after the decimal. Question B: The hot copper is then quenched by dunking the entire rod in a bucket with 10 kg of water at 20 degrees celcius. The specific heat capaciy of water is 4.18 kJ/kg degrees celcius. If none of the water turns to steam what is the equilibrium temp of the copper rod and water? Please give the answer in degrees celcius Question C: You measure the equilbrium temp and find that it is 24 degrees celcius. If the latent heat of vaporization of water is 2,260 kJ/kg, what mass of water turned to steam? Answer in gramsarrow_forwardResearchers are conducting a study to quantity the thermal conductivity of a composite material. A square box is made from 1932 cm2 sheets of the composite insulating material that is 5.2 cm thick. A 125 W heater is placed inside the box. Sensors attached to the box show that the interior and exterior surfaces of one face have reached the constant temperatures of 71°C and 23°C. What is the thermal conductivity in W/m-K?arrow_forwardQ11: Consider a homogeneous spherical piece of radioactive material of radius ro =0.04 m that is generating heat at a constant rate of g'= 4 x 10' W/m?. The heat generated is dissipated to the environment steadily. The outer surface of the sphere is maintained at a uniform temperature of 80°C and the thermal conductivity of the sphere is k = 15 W/m °C. Assuming steady one-dimensional heat transfer, (a) express the differential equation and the boundary conditions for heat conduction through the sphere, (b) obtain a relation for the variation of temperature in the sphere by solving the differential equation, and (c) determine the temperature at the center of the sphere.arrow_forward
- A glass window is 3.7 mm thick, is 2.29 m tall by 1.04 m wide, and has a thermal conductivity of 1.0 W/m K. What is the rate of heat loss (in W) through the window if the inside temperature is 22.3° C and the outside temperature is -20.7 ° C ?arrow_forwardFor a temperature difference ΔT = 20C, one slab of material conducts 10W/m². What is the rate of heat flow per m² of surface area when the slabs are placed side by side with ΔTtot = 20C?arrow_forwardCalculate the overall heat-transfer coefficient of a steel pipe based on the inside area. The inside diameter of the pipe is 10 cm, and the pipe is 2 cm thick. The inside convective heat- transfer coefficient is 350 W/(m2 o C), the outside convective heat-transfer coefficient is 25 W/(m2 o C), the thermal conductivity of the steel pipe is 15 W/(m C). If the pipe is used to convey steam at a bulk temperature of 110 o C and the outside ambient temperature is 20 o C, determine the rate of heat transfer from the pipe.arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning