OCR AS LEVEL 2022 PHYSICS A MARK SCHEME -H156-02 PAPER 2-H156/02: Depth in physics

Question Answer Marks Guidance 1 (a) Use a micrometer / caliper (to measure the diameter of the ball) Repeat readings in different directions and average r = (mean) diameter  2 B1 B1 B1 Ignore radius Allow pla ...

Question Answer Marks Guidance 1 (a) Use a micrometer / caliper (to measure the diameter of the ball) Repeat readings in different directions and average r = (mean) diameter  2 B1 B1 B1 Ignore radius Allow places / points / positions for directions AW (b) ? = 169 − 96 87 or 73 87 ? = 0.169 − 0.096 87 × 10−6 or 0.073 87 × 10−6 ? (= 839) = 840 (kg m–3 ) C1 M1 A0 Ignore power of tens Note power of tens must be seen for both mass and volume (c) volume =4π(8.1×10−3 ) 3 3 or 2.226 × 10–6 (m3 ) OR 840 × 9.81 × candidate’s volume 840 × 9.81 × 2.226 × 10–6 or 0.0183 0.018 (N) C1 M1 A0 Ignore power of tens (d) (i) Terminal velocity is when the velocity is constant (Terminal) velocity is determined from the gradient when graph is a straight line / constant gradient OR evidence of calculation of gradient of straight section B1 B1 B1 Allow acceleration is zero for velocity is constant Check read-offs are appropriate. H156/02 Mark Scheme June 2022 9 Question Answer Marks Guidance (ii) Tangent drawn at t = 0.2 s extends at least two large squares (0.2 s) in the x-direction 1.2 (m s –1 ) M1 A1 Allow 1.10 (m s –1 ) to 1.30 (m s –1 ) (e) ? = 0.017 × 9.81 − 0.018 6? × 8.1 × 10−3 × 1.8 (= 0.14877 6? × 8.1 × 10−3 × 1.8 ) 0.54 kg m-1 s -1 OR N s m-2 OR Pa s C1 A1 B1 Allow 0.55 Note for power of ten errors 607 or 0.607 or 5.4 × 10–4 scores one mark Total 15 H156/02 Mark Scheme June 2022 10 Question Answer Marks Guidance 2 Level 3 (5–6 marks) Clear diagram and procedure and measurements including explanation of the use of one light gate and analysis including determination of Q and R. There is a well-developed line of reasoning which is clear and logically structured. The information presented is relevant and substantiated. Level 2 (3–4 marks) Some procedure, some measurements and some analysis. OR Limited procedure, limited measurements and detailed analysis OR Detailed procedure, detailed measurements and limited analysis There is a line of reasoning presented with some structure. The information presented is in the most-part relevant and supported by some evidence. Level 1 (1–2 marks) limited procedure and limited measurements and limited analysis There is an attempt at a logical structure with a line of reasoning. The information is in the most part relevant. 0 marks No response or no response worthy of credit. B1 x 6 Indicative scientific points may include: Diagram and procedure • labelled diagram including light gate positioned at P • card added to trolley to interrupt light beam • description of procedure • repeats experiment for each M • keep d constant • method to keep d constant, e.g. mark start position • method to stop trolley hitting pulley / load hitting floor e.g. cushion / sand bag • method to fix M to the trolley • use a release mechanism Measurements • use ruler to measure length of card / object interrupting light beam • use of balance to determine M • method to determine W • use of ruler to measure d. Analysis • v = length of card ÷ time • plot a graph of 1/v 2 against M (or equivalent graph • gradient = 1 2??−? • R = y-intercept • Q = 2?? − 1 gradien