2.4 Again consider equation (2.26). Assume the sphere is made of silicon, initially the temperature of the sphere is 1000K, and that the ambient environment is at 300K. If the sphere has radius 10m, how long does it take for the center of the sphere to cool to 99 percent of its steady-state value? Repeat the calculation if the sphere is 100m,1cm, and 1m in radius. [Note: Equation 2.26 has errors - use the expression from class; look up required properties for silicon; by cooling to 99% of steady-state value, we mean cooling to 307K ( 99% of the way from 1000K to 300K) ] T(r,t)=T(T0T)n=1nr2R(1)nsin(Rnr)eR2n2r2kt