A rocket engine is spherical in shape and $100cm$ in diameter. Thermal conductivity is $10\frac{W}{m}K$ and thickness is $10mm.$ It is covered with $2$ layers of insulation $10cm$ and $20cm$ thick respectively. Thermal conductivities are $5\frac{W}{m}K$ and $1\mathrm{.}1\frac{W}{m}k$ respectively. Find the heat loss when the temperatures of inside and outside surfares ant $120.$ and $100C$ respectively