Chapter A.8, Problem 60AYU

To determine

To find: What is the average speed from Chicago to Miami?

Answer to Problem 60AYU

$\text{49}\text{.5}$ mph.

Explanation of Solution

Given:

In going from Chicago to Atlanta, a car averages $45$ miles per hour, and in going from Atlanta to Miami, it averages $55$ miles per hour. If Atlanta is halfway between Chicago and Miami, Discuss an intuitive solution. Write a paragraph defending your intuitive solution.

Calculation:

The car travels at each speed for half the distance, not half the trip (time).

So, the car travels $45$ mph for $55\%$ of the time and $55$ mph for the other $45\%$.

$45\left(.55\right)+55\left(.45\right)=24.75+24.75=49.5$ mph