Question

An automobile travels the first half of an 80.0 mi trip at 20.0 mi/h and the second half of the trip at 40.0 mi/h. What is the average speed for the entire trip?

Answer 1

This question involves the concepts of uniform speed motion and average speed.

The average speed for the entire trip is "26.67 mi/h".

First, we need to find out the total time taken for the entire trip. For that purpose, we will break the entire trip into two halves of uniform speed motion:

$Total\ Time = t_1+t_2\\\\Total\ Time = \frac{s_1}{v_1}+\frac{s_2}{v_2}\\\\Total\ Time = \frac{40\ mi}{20\ mi/h}+\frac{40\ mi}{40\ mi/h}\\\\Total\ Time = 2\ h + 1\ h\\Total\ Time = 3\ h$

Now, the average speed for the entire trip will be:

$Average\ Speed = \frac{Total\ Distance}{Total\ Time}\\\\Average\ Speed =\frac{80\ mi}{3\ h}$

Average Speed = 26.67 mi/h

Learn more about average speed here:

https://brainly.com/question/12322912?referrer=searchResults

The attached picture explains the concept of average speed.