Question 31 - Problems - Chapter 2

Problem:

A horse trots around a quarter-mile track three complete times in 1 min 40 s.

Question:

a) What is the average speed?

b) What is the average velocity?

Solution:

The horse runs around a track so his displacement $\Delta s = 0m$

The traveled way against it is $s = 3x0.25mile = 0.75$ mile

The time to complete his race is $t = 1m40s$

import numpy as np
import pint
u = pint.UnitRegistry()
d_s = 0 * u.m
s = 3 * 0.25 * u.mile
t = 1*u.min + 40 * u.s
v_v = d_s / t
v_s = s/t
print(f'a) The average speed is: {v_s.to(u.m / u.s):.1f}')
print(f'b) The average velocity is: {v_v.to(u.m / u.s):.1f}')

a) The average speed is: 12.1 meter / second
b) The average velocity is: 0.0 meter / second