Question

based on this graph, which chart represents the energy for point a?
height (m) vs. time (s)

10 10
ep ek

12
ep ek

12
ep ek

Explanation:

To solve this, we analyze the energy at point A (height - time graph) and relate it to potential (\(E_p\)) and kinetic (\(E_k\)) energy:

Step 1: Understand Energy at Point A

Point A has a height (so \(E_p\) exists) and is moving (so \(E_k\) exists). Total mechanical energy (\(E_{total} = E_p + E_k\)) is conserved (assuming no air resistance). From the height - time graph, at the peak (e.g., first peak ~20 m), total energy would be higher, but at point A (height ~10 m), we analyze the bar charts:

• First chart: \(E_p = 10\), \(E_k = 10\) (total = 20).
• Second chart: \(E_p = 12\), \(E_k = 0\) (implies no motion, but point A is moving).
• Third chart: \(E_p = 0\), \(E_k = 12\) (implies no height, but point A has height).

Step 2: Match Energy to Point A

Point A has both \(E_p\) (due to height) and \(E_k\) (due to motion). The first chart has \(E_p = 10\) (matches height - related \(E_p\)) and \(E_k = 10\) (matches motion - related \(E_k\)), with total energy consistent with conservation (sum to 20, plausible for the system). The other charts fail: second has \(E_k = 0\) (no motion, incorrect), third has \(E_p = 0\) (no height, incorrect).

Answer:

The first chart (with \(E_p = 10\) and \(E_k = 10\))