A spherical pressure vessel of 8.0 meter diameter is used to store liquid nitrogen gas at -40°C. An insulation with a thermal conductivity of 0.085 W/m-K and thickness 350 mm is applied to the tank to reduce the heat transfer. a) Determine the radial position in the insulation layer at which the temperature is 0°C when ambient air temperature is 20°C and the convection coefficient is 6 W/m²K. b) Repeat the same problem by considering contact resistance between sphere and the insulation of 0.2 K/W.

Agas contained within a piston-cylinder assembly e end nation about same energy states, 1 and 2, where pi 10 bar, v undergoes two processes, a and b, between the sam 0.1 m3, ui-400 kj and p2 1 bar, v2 1.0 m2, u2 200 kj: process a: process from 1 to 2 during which the pressure- volume relation is pv constant process b: constant-volume process from state 1 to a pressure of 2 bar, followed by a linear pressure-volume process to +20 0 state 2 kinetic and potential energy effects can be ignored. for each of the processes a and b, (a) sketch the process on p-v coordinates, (b) evaluate the work, in kj, and (c) evaluate process the heat transfer, in kj