Basic Algebra Question about speed

80 Views Asked by At

Hi I just want to check this. It's from a recent test I took and the answer I got didn't match any of the choices. If a car travels $x$ miles at $Y$ miles per hour, and then another $x$ miles at $Z$ miles per hour, what is the average speed during the trip? It should just be the total miles divided by the total time right? That's $$\frac{2x}{\frac{x}{Y} + \frac{x}{Z}}$$

1

There are 1 best solutions below

1
On

Be careful about average velocity and average speed. If you want to calculate average speed, then your calculation is ok. But average velocity is $ \frac{displacement}{time}$. So if the car moves x miles to the east and then x miles to the west, then the average velocity is $0$.