//Given that
m = 4.0* 10^-6  //in kg
l = 0.77 * 10^-3  //in meter
h = 0.30  //in m
g = 9.8  //in m/s^2

//Sample Problem 9-9
printf("**Sample Problem 9-9**\n")
//Using Work-Energy theorem
//F * l = mgh
F = m* g* h/l
printf("The external force on the betal is %fN", F)