I am a little confused about the average speed of a journey.
If I travel at 40mph for the first 100 miles of the journey and then 60mph for the other 100 miles of the 200 mile journey, then is my average speed of the journey 50mph?
If I use the formula:
$$ \text{Average speed} = \frac{\text{Total distance}}{\text{Total time}},$$
then I get
$$\text{Average speed}= \frac{100+100}{\frac{5}{2}+\frac{5}{3}} =48\text{mph}.$$
I don’t quite understand why I get different answers?
Best Answer
The average is below 50 because you are traveling at the lower speed for a longer period of time
This is why, if you run the 400m on a 400m track, your best option is to have no wind... the advantage you would get from having the wind in your back is less than the disadvantage from running into the wind since you are running into the wind for a longer period