A cross-country runner runs 10 miles in 40 minutes. What is their average speed?

15mil/hr

Explanation:

To make the average speed in mph, we need to get the 40 minutes to an hour. We multiply 40 minutes by 3/2 to get 60 minutes or an hour.

40 x (3/2) = 60

This means that we need to multiply 10 miles by 3/2:

10 x (3/2) = 15 (we get 15 miles)

Average speed is equal to distance over time.

Average speed is 15mil/hr.

Hope this helps!

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.