sphere made of giass, 20 mm in diameter, is ot a unil orm tempecature of te.B"c. Now the sphere is ploced in air flow ot igorc to cool donm. The ean wetion renpoctively. Dotermine the surtace temperoture of the sphere in /ocl when the center of the sphare reaches 30 C The tolotcince of vour antwer is in. Coefficients used in the one-term approximation to the series solutions for transient one-dimensional conduction