CAIE IGCSE Physics Spring Constant
Practise calculating spring constant, force or extension with k = F/x, extracting extension from length data and determining k experimentally or from a graph.
- Syllabus
- 2026–2028
- Course
- Physics 0625
Practise calculating spring constant, force or extension with k = F/x, extracting extension from length data and determining k experimentally or from a graph.
A force is a vector quantity.
A student suspends a spring from a clamp stand and measures the length l0 of the spring.
Fig. 2.1 shows the apparatus.

Fig. 2.1 (not to scale)
The student then suspends loads of different weights from the spring and measures the length of the spring for each load. He then plots a graph of the length of the spring against weight.
Fig. 2.2 is the graph that the student plots.

Fig. 2.2
Using Fig. 2.2, determine the spring constant of this spring.
spring constant =
22 N/m ≤ k ≤ 25 N/m
A3
clear subtraction of 0.12 from a length that is in Hooke’s law region e.g. 0.54 – 0.12
C1
k = F/x in any form OR k = W/x in any form OR k = 1/gradient
C1