Edgefield 6091_4E_PRELIM_P2_2024_markschemeP2

Edgefield Secondary School 2024 Sec 4E Pure Physics PRELIM Exam Marking Scheme Page 1 Subject : 6091 Pure Physics Level : Secondary 4 Express Exam : 2024 Prelim Examination Paper : Paper 2 Note : -No mark is given if the answer has no unit or wrong unit. -Appropriate significant figures/ decimal places for each numerical answer, max 1 mark deducted for entire Paper 2. -ecf marks are only given if they satisfy certain conditions indicated in the Remarks. Paper 2 Qn SECTION A [Workings / Calculations / Methods] Marks / Remarks 1a arrow(head) on chain pointing to the right vertical arrow downwards and part of arrow touching or within rectangle of lights or direction of arrow in (i) and (ii) correct (by eye) 1m 1b scale given (must have unit of cm:N or cm/N or N:cm or N/cm) correct triangle or rectangle (might be implied) and correct resultant (compulsory e.c.f. from (i) or (ii): i.e. correct diagonal according to candidate’s (i) and (ii)) 272 ≤ candidate’s value ≤ 283 N 1m scale 1m correct length/dir weight 1m correct diagram and direction of resultant force Total = 4 m 2a Centre of gravity of any object is defined as the point through which its whole weight appears to act. 1m 2b 2nd quadrant 1m 2c When the centre of gravity is directly above the finger (pivot), the line of action of the weight of the disc lies within the finger. There will be no net moment about the finger and the disc will not topple. Or When the centre of gravity is directly above the finger (pivot), the 1m 1m

Edgefield Secondary School 2024 Sec 4E Pure Physics PRELIM Exam Marking Scheme Page 2 Qn SECTION A [Workings / Calculations / Methods] Marks / Remarks perpendicular distance from the finger to the line of action of the weight of the disc is zero. There will be no net moment about the finger and the disc will not topple. Or When the centre of gravity is not directly above the finger (pivot), the line of action of the weight of the disc lies outside the finger. There will be a moment due to the weight of the disc about the finger that causes the disc to topple over. 2d m = 450 g (2 sf) 1m for correct workings 1m for correct ans/unit 2e OR 1m Total = 7 m 3a i (p =) F/A or 12 000/0.048 = 2.5 × 105 Pa 1m for correct workings 1m for correct ans/unit 3a ii (F =) pA = 12 000 x 0.14 = 35000 N 1m 3b atmospheric pressure or friction (between cylinder and piston/oil) (accept bubbles (of air) in oil or viscosity of oil) 1m 3c (W.D. =) F × d or 12 000 × 0.065 = 780 J 1m for correct workings 1m for correct ans/unit Total = 6 m New hole is twice the size of 1 small hole

Edgefield Secondary School 2024 Sec 4E Pure Physics PRELIM Exam Marking Scheme Page 3 Qn SECTION A [Workings / Calculations / Methods] Marks / Remarks 4a geothermal 1m 4b i (E =) mcθ = 1000 × 4200 × 80 = 3.4 × 108 J 1m for correct workings 1m for correct ans/unit 4b ii  steam condenses or steam