 # PROBLEM 19 # 
Standard formula used 
 E = (n^2 * h^2) / (8 * m * L^2)) 
 p_n = n*h/(2*pi) 

 Energy of electron -
 For (n=1) is 6.019835e-18 J.
 For (n=2) is 2.407934e-17 J.
 Momentum of electron -
 For (n=1) is 3.310000e-24 kg-m/sec.
 For (n=2) is 6.620000e-24 kg-m/sec.
