Question 21 - Problems - Chapter 2

Problem:

The distance for a marathon is 26 mi 385 yd. In 1984, Joan Benoit set an Olympic record with a time of 2 h 24 min 52 s.

Question:

What was her average speed in m/s?

Solution:

Distance $s = 26$ mi $385$ yd

Time $t = 2$ h $24$ min $52$ s

By mean of introduction, we will use the unit conversion modules Pint

# See if the library module "pint" is installed, if not download and install it 
# pint is not installed by default in anaconda
#
# if you want to install in anaconda use this command in the anaconda console:
#     conda install -c conda-forge pint
#
# if you do not use anaconda this script will install pint by the operating system
#
try:  
    import pint
except:
    import os
    os.system('pip install pint')    
    import pint

from datetime import timedelta
u = pint.UnitRegistry()

Time = timedelta(hours=2, minutes=24, seconds=52)
Distance = 26 * u.mile + 385 * u.yd # in m
Speed = Distance.to(u.m) / (Time.total_seconds() * u.s)
print(f'His average speed was {Speed:.1f} . (or {Speed.to(u.km / u.hour):.1f}).')

His average speed was 4.9 meter / second . (or 17.5 kilometer / hour).