An object dropped from rest from the top of a tall building on Planet X falls a distance d(t) = 91 feet in the first t seconds. Find the average rate of change of distance with respect to time as t changes from t, = 5 to t, = 8. This rate is known as the average velocity, or speed, feet The average velocity as t changes from 5 to 8 seconds is sec (Simplify your answer.) de