Question

disk slides along the low-friction surface along the path that is shown. rank the kinetic energy (ke) of the disk at the three marked locations. tap the fields below to rank the locations in terms of their ke. greatest ke middlest ke smallest ke

Explanation:

Step1: Recall Energy Conservation

In a low - friction system, mechanical energy (sum of kinetic energy \(KE\) and potential energy \(PE\)) is conserved. The formula for gravitational potential energy is \(PE = mgh\) (where \(m\) is mass, \(g\) is acceleration due to gravity, and \(h\) is height) and kinetic energy is \(KE=\frac{1}{2}mv^{2}\). So, \(KE + PE=\text{constant}\), which means \(KE=\text{constant}-PE\). Lower height (\(h\)) means lower \(PE\) and higher \(KE\), and vice - versa.

Step2: Analyze Heights of Points

• Point \(C\): From the diagram, it is at the lowest height among \(A\), \(B\), and \(C\). So, its \(PE\) is the lowest. Since \(KE=\text{constant}-PE\), its \(KE\) is the highest.
• Point \(A\): Its height is between that of \(B\) and \(C\). So, its \(PE\) is between that of \(B\) and \(C\), and its \(KE\) is between that of \(B\) and \(C\).
• Point \(B\): It is at the highest height among the three points. So, its \(PE\) is the highest, and thus its \(KE\) is the lowest.

Answer:

Greatest KE: \(C\)
Middlest KE: \(A\)
Smallest KE: \(B\)