Question

you develop a model for a ball that is thrown up into the air then falls to the ground. your model includes only conservative forces. which point of the balls motion could the following bar graph model, where ke is kinetic energy and pe is potential energy? (1 point) when the ball is at its highest point just before the ball reaches the ground when the ball is released into the air just after the ball begins its descent

Explanation:

Step1: Analyze energy at highest point

At the highest point, velocity \(v = 0\), so \(KE=\frac{1}{2}mv^{2}=0\). But in the graph \(KE
eq0\), so it's not when the ball is at its highest point.

Step2: Analyze energy just before reaching ground

Just before reaching ground, height \(h\approx0\), so \(PE = mgh\approx0\). But in the graph \(PE
eq0\), so it's not just before the ball reaches the ground.

Step3: Analyze energy when ball is released

When released, \(h = 0\) (assuming release - point as reference for potential energy), \(PE=mgh = 0\). But in the graph \(PE
eq0\), so it's not when the ball is released into the air.

Step4: Analyze energy just after descent begins

Just after descent begins, the ball has some height (so \(PE=mgh>0\)) and some velocity (so \(KE=\frac{1}{2}mv^{2}>0\)) which matches the bar - graph with both \(KE\) and \(PE\) non - zero.

Answer:

just after the ball begins its descent