GESS_4NA_ScPh_Prelim_P2_22_MS

1 GESS 4NA ScPh P2 Prelim 22 TYL (LTW) GESS Preliminary Exam 2022 Science (Physics) 5105/02 Q Marking Scheme Marker’s Comment 1 (a) gravitational force / weight and force due to wind / air resistance [B1] (b) (i) Either At A, Shirley experienced maximum acceleration due to gravity, 10 m/s2. [B1] Or As speed increases, a ir resistance also increases. [B1] As Shirley fell, she experienced increasing air resistance, the resultant force acting on her decreased and the acceleration decreases. [B1] (ii) C [B1] (iii) EF [B1] 2 (a) T = 0.01 s either [B1] f = 1 / T = 1 / 0.01 or [M1] = 100 Hz and [A1] (b) Either  = v / f Or  = vT = 340 / 100 = 340 × 0.01 = 3.4 m [B1] = 3.4 m [B1]

2 GESS 4NA ScPh P2 Prelim 22 TYL (LTW) Q Marking Scheme Marker’s Comment 3 (a) [B1] for drawing ammeter symbol anywhere along the red path [B1] for drawing voltmeter symbol across the lamps (in parallel) (b) I = 3.75 A, V = 4.50 V current through each lamp = 3.75 / 2 = 1.875 A either [B1] (i) R = V / I = 4.50 / 1.875 or [M1] = 2.4  and [A1] (ii) P = VI = 4.50 × 3.75 [M1] = 16.9 W [A1] A V

3 GESS 4NA ScPh P2 Prelim 22 TYL (LTW) Q Marking Scheme Marker’s Comment 4 (a) vernier calipers [B1] (b) (c) (i) g = W / m = 1.80 / (176.8/1000) = 10.2 N/kg [B1] (ii)  = m / V = 176.8 / (4.01 × 2.04 × 1.12) [M1] = 19.3 g/cm3 [A1] (iii) The bar is very likely to be pure gold as the calculated value is almost the same as the density of pure gold. [B1] (iv) P = F / A = 1.80 / (4.01 × 2.04) [M1] = 0.220 N/cm2 [A1] C

4 GESS 4NA ScPh P2 Prelim 22 TYL (LTW) Q Marking Scheme Marker’s Comment 5 (a) [B1] for plotting all the points correctly with × (allow one error in plotting point) [B1] for drawing best-fit curve × × × × × × × × × × ×

5 GESS 4NA ScPh P2 Prelim 22 TYL (LTW) Q Marking Scheme Marker’s Comment 5 (b) (i) 10 min [B1] (ii) 25C [B1] (iii) 1 Dull black surface [B1] 2 Can A loses heat faster than can B as the temperature of water in can A decreases faster than can B [B1] as dull black surface is good emitter of heat radiation. [B1] (c) Cover both cans with a lid / Wrap both cans with an insulating material [B1]

6 GESS 4NA ScPh P2 Prelim 22 TYL (LTW) Q Marking Scheme Marker’s Com