The average speed of the whole travel is equal to <u>400 mph</u>.
Why?
From the statement, we know that whole travel is divided into three parts. For the first part (traveling from New York to Chicago), we have that it was 3.25 hours and the covered distance was half of the total distance (1400mi). For the second part, we have that it was 1 hour (layover time), and the covered no distance. For the third part (traveling from Chicago to Los Angeles), we have that it was 2.75 hours, and it took the other half of the total distance (1400mi).
We can calculate the average speed of the whol travel using the following formula:
![AverageSpeed=\frac{distance_{1}+distance_{2}+distance_{3}}{time_{1}+time{2}+time_{3}}](https://tex.z-dn.net/?f=AverageSpeed%3D%5Cfrac%7Bdistance_%7B1%7D%2Bdistance_%7B2%7D%2Bdistance_%7B3%7D%7D%7Btime_%7B1%7D%2Btime%7B2%7D%2Btime_%7B3%7D%7D)
Now, substituting and calculating, we have:
![AverageSpeed=\frac{1400mi+0mi+1400mi}{3.25h+1h+2.75h}](https://tex.z-dn.net/?f=AverageSpeed%3D%5Cfrac%7B1400mi%2B0mi%2B1400mi%7D%7B3.25h%2B1h%2B2.75h%7D)
![AverageSpeed=\frac{2800mi}{7h}=400mph](https://tex.z-dn.net/?f=AverageSpeed%3D%5Cfrac%7B2800mi%7D%7B7h%7D%3D400mph)
Hence, we have the average speed of the whole travel is equal to 400 mph.
Have a nice day!
I looked up the question and got D- a vacuum
The ultimate source of energy that powers the sun is the Mass energy of hydrogen fusing into helium, there is no other process than the annihilation of mass to give energy that has been advocated by Albert Einstein and it is capable of keeping the sun alive.