How Do Velocity and Acceleration Change When a Ball Falls?

[@d@m]

1. A ball falls from rest from a height of 16 m and hits the ground after 4.0 s.
(a) What was the velocity of the ball after 4.0 seconds?
(b) What is the acceleration of the ball?

Homework Equations

The Attempt at a Solution

(a) v=d/t = 16m/4.0s = 4.0 m/s (down)
(b) a = v2-v1/t = 4.0m/s-0.0m/s/4.0 s = 1.0m/s/s

 

[Delphi51]

Unless we are dealing some other planet here, you know the acceleration is 9.81 m/s^2 downward. So you can't use v =d/t, which is a constant speed formula.