Chapter 12.4, Problem 53P

8 mm- Top view -200 mm-180 mm- D B B 12 mm Side view B -8 mm D PROBLEM 1.56 In an alternative design for the structure of Prob. 1.55, a pin of 10-mm-diameter is to be used at A. Assuming that all other specifications remain unchanged, determine the allowable load P if an overall factor of safety of 3.0 is desired. PROBLEM 1.55 In the structure shown, an 8- mm-diameter pin is used at A, and 12-mm- diameter pins are used at B and D. Knowing that the ultimate shearing stress is 100 MPa at all connections and that the ultimate normal stress is 250 MPa in each of the two links joining B and D, determine the allowable load P if an overall factor of safety of 3.0 is desired. 20 mm P 8 mm- 12 mm- Front view

Where on the beam below is the Maximum Deflection likely to occur? 2P A "ती Point A Point B Point C Point D Point B or Point D ८ B प

Sign in ||! PDE 321 proje X IMB321 PDF Lecture 5 X PDF Planet Ec X PDF Planet Ec X PDF PEABWX PDF meeting x PDF GSS Quo X PDF File C:/Users/KHULEKANI/Downloads/CIVE%20281%20Ass-2.pdf Draw | | All | a | Ask Copilot + 1 of 7 | D SOLUTION B PROBLEM 12.16 Block 4 has a mass of 40 kg, and block B has a mass of 8 kg. The coefficients of friction between all surfaces of contact are μ, = 0.20 H = 0.15. Knowing that P = 50 N→, determine (a) the acceleration of block B, (b) the tension in the cord. Constraint of cable: 2x + (x-x1) = x + x = constant. a+ag = 0, or aB = -a Assume that block A moves down and block B moves up. Block B: +/ΣF, = 0: NAB - WB cos 0 = 0 =ma: -T+μN + Wsin = We as g + ΣΕ We Eliminate NAB and aB- NAB B Nas HN UNA A NA -T+W(sin+μcоsе) = WB- g VD"M- g Block A: +/ΣF, = 0: NA-NAB - W₁cos + Psinė = 0 N₁ = N AB+W cose - Psin = (WB+WA)cose - Psinė ΣF=ma -T+Wsino-FAB-F + Pcos = CIVE 281 X + Ждал g Q | го || حالم ☑

Where on the below beam is the Maxiumum Slope likely to occur? 120 Point A Point B Point C Point B or Point C B с

A very thin metallic sheet is placed between two wood plates of different thicknesses. Theplates are firmly pressed together and electricity is passed through the sheet. The exposed surfaces ofthe two plates lose heat to the ambient fluid by convection. Assume uniform heating at the interface.Neglect end effects and assume steady state.[a] Will the heat transfer through the two plates be the same? Explain.[b] Will the exposed surfaces be at the same temperature? Explain

Design consideration requires that the surface of a small electronic package be maintained at atemperature not to exceed 82 o C. Noise constraints rule out the use of fans. The power dissipated inthe package is 35 watts and the surface area is 520 cm2 . The ambient temperature and surroundingwalls are assumed to be at 24 o C. The heat transfer coefficient is estimated to be 9.2 W/m2- oC andsurface emissivity is 0.7. Will the package dissipate the required power without violating designconstraints?

Consider radiation from a small surface at 100 oC which is enclosed by a much larger surface at24 o C. Determine the percent increase in the radiation heat transfer if the temperature of the smallsurface is doubled.

A small electronic package with a surface area of 820 cm2 is placed in a room where the airtemperature is 28 o C. The heat transfer coefficient is 7.3 W/m2 - o C. You are asked to determine if it isjustified to neglect heat loss from the package by radiation. Assume a uniform surface temperature of78 o C and surface emissivity of 0.65 Assume further that room’s walls and ceiling are at a uniformtemperature of 16 o C.

A hollow metal sphere of outer radius or = 2 cm is heated internally with a variable output electricheater. The sphere loses heat from its surface by convection and radiation. The heat transfercoefficient is 22 W/ m2 - o C and surface emissivity is 0.92. The ambient fluid temperature is 20 o C andthe surroundings temperature is 14 oC. Construct a graph of the surface temperature corresponding toheating rates ranging from zero to 100 watts. Assume steady state. Use a simplified model forradiation exchange based on a small gray surface enclosed by a much larger surface at 14 o C.