#The natural logarithm is called log in python
from math import log, pi

M = 67
c = 3.7
rho = 1.038
K = 5.4e-3
Ty = 70
Tw = 100


T0 = 20.0
time = (M**(2.0/3)*c*rho**(1.0/3))/(K*pi**2*(4*pi/3)**(2.0/3)) \
        *log(0.76*(T0-Tw)/(Ty-Tw))


print("When starting from %g degrees, it takes %g minutes \
and %g seconds to reach %g degrees." %(T0, int(time/60),int(time%60),Ty))

"""The excercise just asks us to print the time, so we could
just print it in seconds. To make the result more readable we
convert to minutes and seconds and present the results without
decimals. Ordinary division (/) and the modulo operator (%) are
used for the conversion. """

"""
Terminal> python egg.py
When starting from 4 degrees, it takes 6 minutes and 36 seconds to reach 70 degrees.
Terminal> python egg.py
When starting from 20 degrees, it takes 5 minutes and 15 seconds to reach 70 degrees.
"""