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9702/31 — Paper 3 Advanced Practical Skills 1

Cambridge Assessment International Education · October/November 2025

DOCUMENTS
CI · QP · MS
TOTAL PAGES
31
QUESTIONS
19
MARKS
40
Sit this paper →

WHAT THIS PAPER ASKS YOU TO DO

Question 1PRACTICAL

Spring oscillations: series vs parallel stiffness

Time oscillations of a mass on a 'double spring' (two springs in series) and then on two springs in parallel, then vary the mass and plot √T2 against √T1.

[20]
  1. 1(a)(i)Slide the double spring and the two single springs onto the longer wooden rod (Fig. 1.1). Fix the rod approximately 55 cm above the bench. Hang a total mass of 270 g from the double spring; this mass is m. Record m.[1]
  2. 1(a)(ii)Gently pull the mass down through a short distance and release. Take measurements to determine the period T1 of the oscillations.[2]
  3. 1(b)Using the shorter wooden rod (with its two notches), hang mass m from the two single springs in parallel instead (Fig. 1.2), keeping the rod level. Pull down gently and release, then take measurements to determine the period T2 of the oscillations.[1]
  4. 1(c)Vary m and, for each value, determine T1 and T2 as above. Do not use values of m less than 200 g. Repeat until you have five sets of values of m, T1 and T2. Record your results in a table, including values of √T1 and √T2.[8]
  5. 1(d)(i)Plot a graph of √T2 (y-axis) against √T1 (x-axis) using your results from 1(c).[3]
  6. 1(d)(ii)Draw the straight line of best fit through your plotted points.[1]
  7. 1(d)(iii)Determine the gradient and the y-intercept of your line of best fit.[2]
  8. 1(e)It is suggested that √T2 = P√T1 + Q, where P and Q are constants. Using your answers to 1(d)(iii), determine the values of P and Q, giving appropriate units.[2]
Sit this question →Run it on the guided bench →
Question 2PRACTICAL

Deformation of paper cylinders

Roll paper into a cylinder, squash it under a spring-loaded mass, and test whether the paper's width relates to the springs' change in length as w = k(y − p).

[20]
  1. 2(a)Select the smaller of the two pieces of paper. Measure and record its width w. Roll it into a cylinder held with two paper clips (Fig. 2.2) and adjust until its diameter d is as close as possible to 7.0 cm. Measure and record d.[2]
  2. 2(b)(i)Set up the apparatus of Fig. 2.3: slide the upper spring's loop onto the wooden rod, hang a 200 g mass from the lower spring, and adjust the boss so the bottom of the mass is approximately 10 cm above the bench, with the paper cylinder centred underneath. Measure and record the length of the springs, y.[1]
  3. 2(b)(ii)Estimate the percentage uncertainty in your value of y. Show your working.[1]
  4. 2(c)(i)By adjusting the height of the boss, lower the mass to squash the middle of the paper cylinder until the bottom of the mass is 2.5 cm above the bench (Fig. 2.4). Measure and record the new length of the springs, p.[1]
  5. 2(c)(ii)Calculate (y − p).[1]
  6. 2(d)Using the larger sheet of paper, repeat 2(a), 2(b)(i), 2(c)(i) and 2(c)(ii).[3]
  7. 2(e)(i)Using your data and w = k(y − p), calculate two values of k — one for each sheet of paper.[1]
  8. 2(e)(ii)Justify the number of significant figures that you have given for your values of k.[1]
  9. 2(f)It is suggested that the percentage uncertainty in the values of k is 10%. Using this uncertainty, explain whether your results support the relationship in 2(e).[1]
  10. 2(g)(i)Describe four sources of uncertainty or limitations of the procedure for this experiment. For any measurement uncertainty you describe, state the quantity being measured and a reason for the uncertainty.[4]
  11. 2(g)(ii)Describe four improvements that could be made to this experiment. You may suggest other apparatus or different procedures.[4]
Sit this question →Run it on the guided bench →

What the lab technician is told: exact solutions, concentrations and apparatus to set out. This is where the bench comes from.

QUESTION 1 — APPARATUS

Two of the four expendable springs are pre-connected into one 'double spring' (CI Note 1) before the candidate arrives; the other two are laid loose on the bench.

  • stand— height at least 60 cm2
  • boss2
  • expendable springs— approx. outside diameter 15 mm, coiled length 20 mm, spring constant 25 N/m; two pre-connected as a 'double spring', two left separate4
  • longer wooden rod— approx. diameter 1 cm, length 35 cm1
  • shorter wooden rod— approx. diameter 1 cm, length 12 cm, with two 3 mm × 3 mm notches cut 2.0 cm either side of centre (CI Note 2)1
  • 100 g mass hanger— mass value clearly shown; hook fits the wooden rods1
  • 10 g slotted mass2
  • 50 g slotted mass1
  • 100 g slotted mass2
  • stopwatch— reads to 0.1 s or better1
  • 180° protractor— 1° divisions1
  • metre rule— millimetre scale1

QUESTION 2 — APPARATUS

The two springs here are also pre-connected in series (CI Note 1, Fig. 2.1) before the candidate starts.

  • stand— height at least 60 cm1
  • boss1
  • wooden rod— approx. diameter 1 cm, length 35 cm1
  • expendable springs— approx. outside diameter 15 mm, coiled length 20 mm, spring constant 25 N/m; connected together2
  • sheet of paper— width 21.0 cm, approx. length 30 cm (e.g. A4)1
  • strip of paper— width 6.8 cm, approx. length 30 cm, cut from an A4 sheet1
  • paper clip— approx. length 3 cm4
  • small container— for the paper clips1
  • 100 g mass hanger1
  • 100 g slotted mass1
  • stopwatch— reads to 0.1 s or better1
  • metre rule— millimetre scale1
  • 30 cm ruler— millimetre scale1

⚠ Candidates have access to each experiment's apparatus for one hour; the order they attempt the two experiments in is immaterial. Neither question needs chemicals or hazard labelling.

THE CURATED BENCHES BUILT FROM THIS

Same skills, taught rather than examined — guided step by step, with the apparatus mistakes explained as you make them.

Spring oscillations: series vs parallel stiffness →Deformation of paper cylinders: testing w = k(y − p) →