Key relationship
A=A₀e⁻ᵞᵗ; E=E₀e⁻²ᵞᵗ; E₀≈½mgLA₀².
Physics · Practical apparatus
Pendulum energy dissipation
Track successive maximum swings to see energy lost to damping. Energy falls with the square of amplitude; the light-damping period is approximated by the small-angle undamped period.
Open the interactive experiment →Pendulum energy dissipation
அலைவு வீச்சு குறையும்போது ஆற்றல் அதன் வர்க்கத்துடன் குறையும். தணிவு இயக்க ஆற்றலை வெப்பமாக மாற்றும்.
Key notes, relationships and model limits
Practical tip
Track successive maximum swings to see energy lost to damping. Energy falls with the square of amplitude; the light-damping period is approximated by the small-angle undamped period.
Common trap
Energy is proportional to amplitude squared: if amplitude falls by half, the small-angle energy falls to one quarter.
Model limits
small angles and weak phenomenological damping; graph is the energy envelope, not instantaneous bob position.
What you will learn
Adjust pendulum energy dissipation apparatus, observe its reading and derive the indicated physical quantity.
Try the experiment
Try both scenarios, change one control, and predict the result before checking the graph and readouts.
Think of it this way
Change one input while keeping the others fixed, as you would in a controlled experiment.
Worked example
For m=0.1 kg, L=1 m and A₀=10°, initial energy is ≈14.94 mJ.
Why this matters
The model connects pendulum energy dissipation with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
If swing amplitude halves, its small-angle mechanical energy becomes?
- One half of its previous value.
- One quarter of its previous value.
- Twice its previous value.
Read the explanation
One quarter of its previous value.
Course connection: Virtual apparatus preparation. Check exact board/exam membership in the syllabus sources. Physical practical work remains necessary.