 
 # PROBLEM 2.5 # 
 The value of Beta2 is 1.748516,  The value of Beta2 is -0.252713, 
 We only take the positive value of Beta2 , 
 Hence Beta2=1.75

 Solidification time for slab-shaped casting = 0.671318 hr,
 Solidification time for sphere = 0.054495 hr 