The fatigue data for a ductile cast iron are given as follows: stress amplitude [mpa (ksi)] cycles to failure 248 (36.0) 1 × 105 236 (34.2) 3 × 105 224 (32.5) 1 × 106 213 (30.9) 3 × 106 201 (29.1) 1 × 107 193 (28.0) 3 × 107 193 (28.0) 1 × 108 193 (28.0) 3 × 108

(a) make an s–n plot (stress amplitude versus logarithm cycles to failure) using these data.

(b) what is the fatigue limit for this alloy?

(c) determine fatigue lifetimes at stress amplitudes of 230 mpa (33,500 psi) and 175 mpa (25,000 psi).

(d) estimate fatigue strengths at 2 × 105 and 6 × 106 cycles.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

Find the kinematic pressure of 160kpa. for air, r-287 j/ kg k. and hair al viscosity of air at a temperature of 50°c and an absolute (10 points) (b) find the dynamic viscosity of air at 110 °c. sutherland constant for air is 111k