Question

the diagram shows the conservation of mechanical energy in a pendulum. determine the missing pe and ke

Explanation:

Step1: Find total mechanical energy

At point A, \(PE = 10000J\) and \(KE = 0J\) (assuming it is at maximum height where velocity is \(0\)). So total mechanical energy \(E=PE + KE=10000J\)

Step2: Calculate for point B

Given \(KE = 5000J\). Using \(E=PE + KE\), we get \(PE=E - KE\). So \(PE = 10000 - 5000=5000J\)

Step3: Calculate for point C

Given \(PE = 0J\). Using \(E=PE + KE\), we get \(KE=E - PE\). So \(KE = 10000-0 = 10000J\)

Step4: Calculate for point D

Since energy is conserved \(E = 10000J\). Assume \(PE = 5000J\) (symmetry with point B if motion is symmetric). Then \(KE=E - PE=10000 - 5000 = 5000J\)

Step5: Calculate for point E

Since energy is conserved \(E = 10000J\). Assume \(KE = 0J\) (at maximum height similar to point A). Then \(PE=E - KE=10000-0 = 10000J\)

Answer:

• For point A: \(KE = 0J\)
• For point B: \(PE = 5000J\)
• For point C: \(KE = 10000J\)
• For point D: \(PE = 5000J\), \(KE = 5000J\)
• For point E: \(PE = 10000J\), \(KE = 0J\)