Question

A runner wants to be able to run 400 meters in 50 seconds. What miles-per-hour speed must the runner attain to accomplish this goal? The runner knows that there are 1609 meters in a mile. (round to the nearest whole number)

Answer 1

The runner attain to 18 miles per hour speed.

Explanation:

First we calculate the velocity in meters per second:

`v=e/t`

Where v is velocity, e is distance traveled, and t time taken to travel the distance e.

`v=400m/50sec=8m/s`

So, the speed is 8m/s and now we need to convet to miles per hour.

`(8m/s)/(1609m)*\frac{1mile\int\limits^a_b {x} \, dx }{1hour}*3600s=17,89`

Rounded: 18 miles per hour