DHS 2024 Prelim Phy P4 Soln

Prepared by CKW2024 [For Internal Use Only] [Turn over Answers to 2024 JC2 Preliminary Examination Paper 4 (H2 Physics) Suggested Solutions No. Solution Remark 1(b) x = 15.0 15.0 15.0 cm2 + = Period T = 20.8 20.7 1.04 s2 20 + = [1] - for correct measurements with units - 1 d.p in cm - repeat - X should be within range of 14.0 cm to 16.0 cm [1] - Recorded no of oscillations, n (can be deduced from working) - 1 or 2 d.p in timing - repeat - T in 3 s.f. or 4 s.f. depending on the d.p. of t1 and t2 - t  10.0 s 1(c) x/cm N Time for N oscillation Period T/s T4/s4 t1/s t2/s 11.0 25 24.2 24.1 0.966 0.871 13.0 25 25.1 25.2 1.01 1.04 15.0 20 20.8 20.7 1.04 1.17 17.0 20 21.4 21.6 1.08 1.36 19.0 20 22.1 22.2 1.11 1.52 21.0 20 22.9 22.8 1.14 1.69 [1] - headings and units - 6 sets of data Note: 20T is not accepted as time for 20 oscillations. [1] - d.p. of raw data - t  10.0 s with repeated measurement [1] - s.f. of processed data - correct calculation, allow 1 slip [1] Range of x to be at least 10.0 cm Don’t accept x = 0 cm and x > 26 cm. These will not be considered one set of data. Note: Marks may be deducted for poor presentation: • No table (including border must be drawn) • Table lines not drawn using ruler • Poor presentation of data in table (e.g. Show working in table) 1(d) Refer to attached graph. [1] axes: units, scale (1:1, 1:2 or 1:5 only) [1] plotted points accurate to half of smallest division [1] best fit line MC: For scale, students should use 1:1, 1:2 or 1:5 scale. In most cases, the data obtained would be able to accommodate the use of these scales which are easy to plot to half the smallest division. • Students are allowed to plot their graph in landscape should they find that portrait does not allow for these scales. In general, the use of these

2 scales would also save students some marks for the plotted points mark and the gradient calculations. 1(d) Given T4 = Px + Q Graph of T4 vs x is plotted, where P is the gradient and Q is the y-intercept. ( ) ( )( ) 41 4 1.67 0.89Gradient= 0.0830 20.8 11.4 = 0.0830 s cm Substitute 20.8,1.67 into the equation, 1.67 0.0830 20.8 0.0564 s P Q Q − − =− =+ =− [1] - linearization (statement) [1] - Big triangle - substitution of gradient coordinates accurate to half of smallest division. - P calculated correctly with units [1] Q calculated correctly with units

3 Prepared by CKW2024 [For Internal Use Only] [Turn over

4 No. Solution Remarks 2(a)(i) w = 1.9 +1.9 1.9 mm2 = t = 1.9 +1.9 1.9 mm2 = L0 = 7.5 +7.5 7.5 cm2 = [1] - Repeated w, t & L0 - Recorded w and t to the nearest 0.01 mm with unit - Value of w and t within the range 1.50 to 2.50 mm - Recorded L0 to the nearest mm with unit - Value of L0 within the range 7.0 to 9.0 cm 2(a)(ii) Volume V = (1.910−3)(1.910-3)(27.510−2) = 5.4  10−7 m3 [1] - Correct