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CAIE A-Level Physics 6.1.2 Deformation Terms and Proportional Limit

Practise identifying load, extension, compression and proportional limits from force-extension data, finding unknowns and recognising where Hooke’s law fails.

Syllabus
2028–2030
Course
Physics 9702
Level
AS

Exam points

  • use load, extension and compression precisely when describing a deformed spring or wire
  • read a force–extension graph to identify the limit of proportionality and the point beyond which Hooke’s law no longer applies
  • determine extension, unstretched length or an experimental load from measurements or a force–extension graph

6.1.2—The terms load, extension, compression and limit of proportionality question 1

[Maximum number: 1]

Fig. 4.1 shows the variation with extension x of the tensile force F for two wires, G and H, made from the same material.

Fig. 4.1

Fig. 4.1

The elastic limit has not been exceeded for G or H.

Wires G and H are joined together end-to-end to form a composite wire of negligible weight. The composite wire hangs vertically from a fixed support.

A block of weight of 2.0 N is attached to the end of the wire, as shown in Fig. 4.2.

Fig. 4.2

Fig. 4.2

Use Fig. 4.1 to determine:
- the extension xGx_{\mathrm{G}} of wire G

xG=x_{\mathrm{G}}=

mm
- the extension xHx_{\mathrm{H}} of wire H .

xH=x_{\mathrm{H}}=

mm

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