Cambridge International AS & A Level · 6 · structured
Read the limits of a spring model
Read the limits of a spring model · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- demanding
- Marks
- 9
- Topics
- 4
- Answer
- Complete
An initially0.100m spring is stretched along its axis. Added loads0,1,2,3,4 N give measured lengths0.100,0.104,0.108,0.112,0.118m. Separate compression of another spring changes its length from 0.100m to 0.097m. Assume the displayed values are adequate to locate the departure from proportional behaviour.
- (a)
Explain tensile versus compressive deformation. Define load and extension, find extension at 3 N and compression in the separate spring, and distinguish extension from final length.
4 marks - (b)
State Hooke's law with its condition. Use the data to identify the last clearly proportional load and show why the4 N reading cannot be predicted with the same linear model.
3 marks - (c)
Calculate spring constant from the proportional data, with units.
2 marks
Ready to self-mark?Reveal the detailed answer guide
(a)
Explain tensile versus compressive deformation. Define load and extension, find extension at 3 N and compression in the separate spring, and distinguish extension from final length.
List the given quantities with units, identify the required quantity, write the governing relationship before substituting, and keep extra digits until the final line so rounding does not distort the result.
- 1
Identify force directions and effects for tension/compression.
- 2
Use x=L−L₀=0.112−0.100=0.012m.
- 3
Compression magnitude0.100−0.097=0.003m.
- 4
Define load as force and distinguish change from final value.
(b)
State Hooke's law with its condition. Use the data to identify the last clearly proportional load and show why the4 N reading cannot be predicted with the same linear model.
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
Use extensions0,0.004,0.008,0.012,0.018m.
- 2
State proportional force–extension relation only within the proportional range.
- 3
Compare linear prediction0.016m with observed0.018m; do not claim an exact unmeasured threshold.
(c)
Calculate spring constant from the proportional data, with units.
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
Use force divided by extension, not total length.
- 2
State N m⁻¹.
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) Identify force directions and effects for tension/compression.
- (a) Use x=L−L₀=0.112−0.100=0.012m.
- (a) Compression magnitude0.100−0.097=0.003m.
- (a) Define load as force and distinguish change from final value.
- (b) Use extensions0,0.004,0.008,0.012,0.018m.
- (b) State proportional force–extension relation only within the proportional range.
- (b) Compare linear prediction0.016m with observed0.018m; do not claim an exact unmeasured threshold.
- (c) Use force divided by extension, not total length.
- (c) State N m⁻¹.
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