Cambridge International AS & A Level · 17 · structured
Compare light, critical and heavy damping
Compare light, critical and heavy damping · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- demanding
- Marks
- 8
- Topics
- 2
- Answer
- Complete
Three identical oscillating systems are released from the same positive displacement with zero initial velocity. They differ only in their damping. The equilibrium position is x=0.
- (a)
Explain how a resistive force causes damping and state what happens to the oscillation's mechanical energy.
2 marks - (b)
Define light, critical and heavy damping and sketch displacement–time graphs on common labelled axes for this release.
6 marks
Ready to self-mark?Reveal the detailed answer guide
(a)
Explain how a resistive force causes damping and state what happens to the oscillation's mechanical energy.
Identify what the question is testing, organise the response into distinct mark-earning points, and make every conclusion traceable to a physical principle or to the evidence supplied.
- 1
A resistive force opposes velocity and does negative work on the oscillator.
- 2
Mechanical energy is transferred to thermal/other stores, so free-oscillation amplitude decreases.
(b)
Define light, critical and heavy damping and sketch displacement–time graphs on common labelled axes for this release.
Identify what the question is testing, organise the response into distinct mark-earning points, and make every conclusion traceable to a physical principle or to the evidence supplied.
- 1
Light damping allows repeated crossings of x=0 with a decreasing amplitude envelope.
- 2
Critical damping returns to equilibrium in the shortest time without oscillating.
- 3
Heavy damping also avoids oscillation but returns more slowly than the critical case.
- 4
Draw all curves from the same positive x with zero initial slope; light crosses the axis, critical and heavy approach it from above, with critical returning faster.
- 5
Axes must be displacement and time; do not draw heavy damping as a larger-amplitude oscillation.
Complete marking guidance
Use these worked steps alongside the part-by-part answers. They explain the method and mark allocation; they do not add extra marks.
- (a) A resistive force opposes velocity and does negative work on the oscillator.
- (a) Mechanical energy is transferred to thermal/other stores, so free-oscillation amplitude decreases.
- (b) Light damping allows repeated crossings of x=0 with a decreasing amplitude envelope.
- (b) Critical damping returns to equilibrium in the shortest time without oscillating.
- (b) Heavy damping also avoids oscillation but returns more slowly than the critical case.
- (b) Draw all curves from the same positive x with zero initial slope; light crosses the axis, critical and heavy approach it from above, with critical returning faster.
- (b) Axes must be displacement and time; do not draw heavy damping as a larger-amplitude oscillation.
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