In which situation is the distance traveled proportional to time?

An airplane landing

A soccer ball you kick across a field

A person running on a treadmill at 3
mph for 6

minutes

A 3
-minute ride on a roller coaster

A person running on a treadmill at 3 mph for 6 minutes.

The situation in which the distance traveled is proportional to time is: a person running on a treadmill at 3 mph for 6 minutes.