How Do Velocity and Acceleration Change When a Ball Falls?

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The discussion addresses the physics of a ball falling from a height of 16 meters, taking 4.0 seconds to reach the ground. The calculated velocity after 4.0 seconds is 4.0 m/s downward, but this is incorrect as it uses a constant speed formula. The correct acceleration due to gravity is 9.81 m/s² downward, which should be applied instead of the average velocity formula. The acceleration is constant throughout the fall, and the ball’s velocity increases as it falls. Understanding the distinction between average velocity and instantaneous acceleration is crucial in solving such problems.
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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
 
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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.
 
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