Energy conversion of a falling bob

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SUMMARY

The discussion centers on the energy conversion of a falling bob constrained by a peg. The correct answer to the posed question is option C, which states that the bob has the largest speed when it is vertically below the peg and possesses the same amount of mechanical energy at all times. The misconception that the bob loses energy to the peg is addressed, clarifying that the bob's mechanical energy remains constant throughout its motion, adhering to the principles of conservation of energy.

PREREQUISITES
  • Understanding of mechanical energy conservation
  • Familiarity with pendulum motion dynamics
  • Knowledge of gravitational potential energy and kinetic energy
  • Basic principles of forces acting on objects in motion
NEXT STEPS
  • Study the principles of conservation of mechanical energy in physics
  • Explore pendulum motion and its characteristics
  • Learn about energy loss mechanisms in physical systems
  • Investigate the effects of constraints on motion, such as pegs or barriers
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Students studying physics, particularly those focusing on mechanics and energy conservation, as well as educators seeking to clarify concepts related to pendulum dynamics and energy transformations.

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Homework Statement



A bob is hung by a light string and and is pushed sideways. A peg of wood is placed vertically below the point of suspension of the string to hinder the motion of string as shown in the figure below: (please refer to the attachment)

The bob is released. Which of the following statements is/are correct?
(1) The bob has the largest speed when it is vertically below the peg.
(2) The bob cannot reach the original level when it is at the right side of the peg.
(3) The bob possesses same amount of mechanical energy at all time.

A (1) only
B (2) only
C (1) and (3) only
D (2) and (3) only




Homework Equations





The Attempt at a Solution



I attempted option B, but the answer is C.
For statement (1),
I thought when it is vertically below the peg, it loses some energy to the wood, so the speed is lowered.
 

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Your attachment will take a while to be approved by the mentors, but I will try to answer your question without.

Can I begin by asking you why you believe that the bob would lose some energy to the peg?
 
Last edited:

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