
Consider the water heater We wish to determine the energy needed to compensate for heat losses incurred while the water is stored at the prescribed temperature of 55-degreeC. The cylindrical storage tank (with flat ends) has a capacity of 100 gal, and foamed urethane is used to insulate the side and end walls from ambient air at an annual average temperature of 20-degree C. The resistance to heat transfer is dominated by conduction in the insulation and by free convection in the air, for which h 2 W/m2 middot K. If electric resistance heating is used to compensate for the losses and the cost of electric power is $0.18/kWh, specify tank and insulation dimensions for which the annual cost associated with the heat losses is less than $50.

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Chapter 3 Solutions
Introduction to Heat Transfer
- How to solve this?arrow_forwardA start-up company wants to convert an ICE vehicle into an electric vehicle with the following specification. Power: 250 (HP) horsepower, (note: 1HP = 745 W) Range: 300-miles Fuel economy: 33.5 kilometers per gallon of gasoline. Efficiency of the ICE: 25% Energy Conversion: One gallon of gasoline at 100% efficiency is equal to 33.5 kWh/gallon). a)Calculate the EV consumption rate as Wh/km and find the total energy of the battery pack in KWh to replace the internal combustion engine. b)Design an 8-module battery pack for this full electric vehicle without compromising its range and performance (power). Use commercially available cylindrical cells lithium cell with 20Ah capacity and 3.125 V average voltage. Cell dimensions are 5cm diameter and 10 cm height. The electric motor requires 250 V input that will be provided directly from the battery pack, Report the configuration of each module in…arrow_forward"11-17 The shaft shown in Figure P11-3 was designed in Problem 10-17. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-17, design suitable bearings to support the load for at least 1E8 cycles at 1800 rpm. State all assumptions. (a) Using hydrodynamically lubricated bronze sleeve bearings with Ox = 15, 11d=0.75, and a clearance ratio of 0.001. ✓ ✓ cast-iron roller FIGURE P11-3 Shaft Design for Problems 11-17 b gear key assume bearings act as simple supports 11-19 The shaft shown in Figure P11-4 was designed in Problem 10-19. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-19, design suitable bearings to support the load for at least 5E8 cycles at 1200 rpm. State all assumptions. (a) Using hydrodynamically lubricated bronze sleeve bearings with Oy = 40, 1/d=0.80, and a clearance ratio of 0.002 5. gear gear key FIGURE P11-4 Shaft Design for Problems 11-19 and…arrow_forward
- For the frame below calculate the bending moment at point R. Take P=40 and note that this value is used for both the loads and the lengths of the members of the frame. 2.5P- A Q B R С 45 degrees ✗ ✗ P i 19 Кур -2P- 4PRN -P- -arrow_forwardCalculate the bending moment at the point D on the beam below. Take F=79 and remember that this quantity is to be used to calculate both forces and lengths. 15F 30F A сarrow_forwardShow work on how to obtain P2 and T2. If using any table, please refer to it. If applying interpolation method, please show the work.arrow_forwardcast-iron roller FIGURE P11-3 Shaft Design for Problems 11-17 Chapter 11 BEARINGS AND LUBRICATION 677 gear key P assume bearings act as simple supports 11-18 Problem 7-18 determined the half-width of the contact patch for a 1.575-in-dia steel cylinder, 9.843 in long, rolled against a flat aluminum plate with 900 lb of force to be 0.0064 in. If the cylinder rolls at 800 rpm, determine its lubrication condition with ISO VG 1000 oil at 200°F. R₁ = 64 μin (cylinder); R₁ = 32 μin (plate). 11-19 The shaft shown in Figure P11-4 was designed in Problem 10-19. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-19, design suitable bearings to support the load for at least 5E8 cycles at 1200 rpm. State all assumptions. (a) (b) Using hydrodynamically lubricated bronze sleeve bearings with ON = 40, 1/ d=0.80, and a clearance ratio of 0.002 5. Using deep-groove ball bearings for a 10% failure rate. *11-20 Problem 7-20 determined the…arrow_forwardCalculate the shear force at the point D on the beam below. Take F=19 and remember that this quantity is to be used to calculate both forces and lengths. 15F A сarrow_forward"II-1 The shaft shown in Figure P11-I was designed in Problem 10-1. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-1, design suitable bearings to support the load for at least 7E7 cycles at 1500 rpm. State all assumptions. (a) Using hydrodynamically lubricated bronze sleeve bearings with Ox = 20, 1/d=1.25, and a clearance ratio of 0.001 5. assume bearings act as simple supports FIGURE P11-1 Shaft Design for Problem 11-1 11-2 The shaft shown in Figure P11-2 was designed in Problem 10-2. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-2, design suitable bearings to support the load for at least 3E8 cycles at 2.500 rpm. State all assumptions. (a) Using hydrodynamically lubricated bronze sleeve bearings with ON=30, 1/d=1.0, and a clearance ratio of 0.002. FIGURE P11-2 Shaft Design for Problem 11-2 Table P11-1 Data for Problems assume bearings act as simple…arrow_forwardFor the frame below, calculate the shear force at point Q. Take P=13 and note that this value is used for both the loads and the lengths of the members of the frame. 1 A Q ✗ 19 KBP 2.5P- B R C 45 degrees ✗ 1 .2P- 4PhN -P→arrow_forwardCalculate the Bending Moment at point D in the frame below. Leave your answer in Nm (newton-metres) J J A 2m 2m <2m х D 不 1m X E 5m 325 Nm 4x 400N/marrow_forwardIn the beam below, calculate the shear force at point A. Take L=78 and remember that both the loads and the dimensions are expressed in terms of L. 143 1 DX A - Li 4 LhN 14LRN/m Х B 22 3 L.arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_iosRecommended textbooks for you
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