Question

use the chart to answer the question.
you develop a model for an object on a spring that is dropped, then bounces back up in periodic motion. your model includes only conservative forces. which point of the objects motion could the following bar graph model, where ke is kinetic energy and pe is potential energy?
(1 point)
○ shortly after the object starts moving up
○ when the object is at the lowest point
○ halfway through the objects descent
○ shortly after the object starts falling

Explanation:

Step1: Analyze the energy at each option

• Shortly after the object starts moving up: The object has both kinetic energy (since it's moving) and potential energy (due to its position). But the bar - graph shows only potential energy.
• When the object is at the lowest point: At the lowest point of a spring - mass system (assuming the model is of a vertical spring), the velocity of the object is \(v = 0\) (momentarily at rest at the extreme position). So, \(KE=\frac{1}{2}mv^{2}=0\). The spring is maximally stretched (or compressed), so it has maximum potential energy (either elastic potential energy if we consider the spring's deformation or gravitational potential energy depending on the reference frame, but in a conservative force model, the total mechanical energy \(E = KE+PE\) is conserved).
• Halfway through the object’s descent: The object is in motion, so \(KE

eq0\).

• Shortly after the object starts falling: The object is in motion (accelerating downwards), so \(KE

eq0\).

Answer:

when the object is at the lowest point