Question 8 of 20 This question: 1 p The distance an object falls (when released from rest, under the influence of Earth's gravity, and with no air resistance) is given by d(t) = 16t2, where d is measured in feet and t is measured in seconds. A rock climber sits on a ledge on a vertical wall and carefully-observes the time it takes for a small stone to fall from the ledge to the ground. a. Compute d' (t). What units are associated with the derivative, and what does it measure? b. If it takes 7.1 s for a stone to fall to the ground, how high is the ledge? How fast is the stone moving when it strikes the ground (in miles per hour)? a. d'(t) = The units associated with the derivative are and it measures the of the stone . b. The ledge is feet high . ( Round to the nearest integer as needed.) The stone is moving at mi/hr when it strikes the ground . ( Round to the nearest integer as needed . ) K Next