You are going to test given equation x= 16t^2. You begin the stopwatch and at same time shout to the friend standing on roof of the building 32 feet above you. On hearing you, the friend drops the ball. When you hear it hit ground, you stop the stopwatch to record time t'. This is not exactly time needed for body to fall as it also has delays for human reaction time (assume reaction time is 1/4 second) and time for sound of shout to travel.
i) How to correct t' to give true time of descent?
ii) Redesign experiment to make the factors irrevelant?