On a day when the temperature is 20°C, a concrete walk is poured in such a way that its end are unable to move. (A) what is the stress in the cement when its temperature is 50°C on a hot, sunny day? (B) Does the concrete fracture? Take Young's modulus for concrete to be 7.00 ×10^9 N/m^2

Which situation will have the highest resistance? a.long wire and high temperatureb.short wire and high temperaturec.long wire and cold temperaturedshort wire and low temperature

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

You can decrease the resistance of a length of wire by