Chapter 9, Problem 124P

hand-written solution only please

a 300n girl and an 400n boy stand on a 16m platform supported by posts A and B. The platform itself weighs 200N. What are the forces exerted by the supports on the platform?

C A cylindrical piece of steel 38 mm (1½ in.) in diameter is to be quenched in moderately agi- tated oil. Surface and center hardnesses must be at least 50 and 40 HRC, respectively. Which of the following alloys satisfy these requirements: 1040, 5140, 4340, 4140, and 8640? Justify your choice(s).

Using the isothermal transformation diagram for a 1.13 wt% C steel alloy (Figure 10.39), determine the final microstructure (in terms of just the microconstituents present) of a small specimen that has been subjected to the following time-temperature treatments. In each case assume that the specimen begins at 920°C (1690°F) and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure. (a) Rapidly cool to 250°C (480°F), hold for 103 s, then quench to room temperature. (b) Rapidly cool to 775°C (1430°F), hold for 500 s, then quench to room temperature. (c) Rapidly cool to 400°C (750°F), hold for 500 s, then quench to room temperature. (d) Rapidly cool to 700°C (1290°F), hold at this temperature for 105 s, then quench to room temperature. (e) Rapidly cool to 650°C (1200°F), hold at this temperature for 3 s, rapidly cool to 400°C (750°F), hold for 25 s, then quench to room temperature. (f) Rapidly cool to 350°C (660°F), hold for…

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A 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…

"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…

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- -