Physical Science Controlled Test 1 - 2023 Gauteng Department of Education Johannesburg North District (D10) GRADE 12 PHYSICAL SCIENCES CONTROLLED TEST 1 17 MARCH 2023 MARKING GUIDELINES MARKS: 100 TIME: 2 Hours Physical Sciences Controlled Test 1 - 2023 2 SECTION A: PHYSICS QUESTION 1 1.1 A (2) 1.2 B (2) 1.3 C (2) [6] QUESTION 2 2.1 When a resultant/net force acts on an object, the object will accelerate in the direction of the force at an acceleration directly proportional to the forceand inversely proportional to the mass of the object OR The resultant/net force acting on an object is equal to the rate of change of momentum of the object (in the direction of the resultant/net force.) (2) 2.2 Accepted Labels w Fg/Fw/w/weight/19,6 N/gravitational force T FT/Tension/ fk f / friction / F FA/ Fapplied / 20 N N Normal force / FN Notes • Mark is awarded for label and arrow. • Do not penalise for length of arrows. • Deduct 1 mark for any additional force. • If all forces are correctly drawn and labelled, but no arrows, deduct 1 mark. • Accept FA represented as its horizontal and vertical components 2.3.1 fk = µkN (5) fk = µk(w – Fsinθ) fk = (0,2)(19,6 – 20sin20°) fk = 2,55 N (4) Physical Sciences Controlled Test 1 - 2023 3 2.3.2 POSITIVE MARKING FROM 2.3.1 2 kg block Fnet = ma T – fk - Fx = ma T – 2,55 – 20cos20°= 8 T = 29,34 N X kg block Fnet = ma w – T = ma (m)(9,8) – 29,34 = m(4) 5,8m = 29,34 m = 5,06 (5,059) kg (5) [16] QUESTION 3 3.1 Motion of an object upon which the only force acting is the force of gravity (gravitational force). (2 or 0) (2) 3.2 9,8 m.s-2 downwards (No marks if no/incorrect units or direction) (1) 3.3.1 UPWARDS AS POSITIVE UPWARDS AS NEGATIVE vf2 = vi2 + 2aΔy vf2 = vi2 + 2aΔy vf2 = 02 + 2(-9,8)(-8) vf2 = 02 + 2(9,8)(8) vf = -12,52 m.s-1 vf = 12,52 m.s-1 3.3.2 ∴ vf = 12,52 m.s-1 ∴ vf = 12,52 m.s-1 UPWARDS AS POSITIVE UPWARDS AS NEGATIVE vf = vi + aΔt vf = vi + aΔt -12,52 = 0 + (-9,8)(Δt) 12,52 = 0 + (9,8)(Δt) Δt = 1,2775..s (1,28) Δt = 1,2775..s (1,28) Δt = 1,2775 – 0,6 = 0,6775.. (0,68) Δt = 1,2775 – 0,6 = 0,6775.. (0,68) Δy = viΔt + ½ aΔt2 Δy = viΔt + ½ aΔt2 -8= vi(0,677..)+ ½(-9,8)(0,677..)2 8= vi(0,677..)+ ½(9,8)(0,677..)2 vi = -8,49 m.s-1 ∴ vi = 8,49 m.s-1 3.4 (3) vi = 8,49 m.s-1 (8,43 – 8,49) ∴ vi = 8,49 m.s-1 (8,43 – 8,49) OPTION 1 UPWARDS AS POSITIVE UPWARDS AS NEGATIVE vf2 = vi2 + 2aΔy vf2 = vi2 + 2aΔy (4) (0)2 = vi2 + 2(-9,8)(6,5) (0)2 = vi2 + 2(9,8)(-6,5) vf = 11,29 m.s-1 vf = -11,29 m.s-1 vf = 11,29 m.s-1 upwards vf = 11,29 m.s-1 upwards (3) Physical Sciences Controlled Test 1 - 2023 4 OPTION 2 Emech(i) = Emech(f) (mghi + ½mvi2) = (mghf + ½mvf2) m(-9,8)(0) + ½mvi2 = m(-9,8)(6,5) + ½m(0)2 (3) vi = 11,29 m.s-1 OPTION 3 Can accept options using work calculations such as: Wnc = ΔEK + ΔEP or Wnet = ΔEK (However very unlikely any learners would use these options as Work, Energy and Power is only taught in Term 2) 3.5 POSITIVE MARKING FROM 3.3.1 and 3.4 Marking criteria Correct shape Similar gradients Velocity values (12,52 and 11,29) 3.4 UPWARDS AS POSITIVE UPWARDS AS NEGATIVE (3) Physical Sciences Controlled Test 1 - 2023 5 QUESTION 4 4.1 The total linear momentum in an isolated (closed) system remains constant (is conserved) (2 or 0) 4.2 Δp = m(vf – vi) = 500(-1 – 5) = - 3 000 kg∙m∙s-1 = 3 000 kg∙m∙s-1 West (-1 if no direction) 4.3 (2) (3) POSITIVE MARKING FROM 4.2 FnetΔt = m(vf – vi) = Δp Fnet(1,4) = - 3 000 Fnet = - 2 142, 86 N (3) Magnitude = 2 142,86 N 4.4 EAST AS POSITIVE Σpi = Σpf 1 mark for any (500)(+5) + m2(0) = (500)(-1) + m2(3) m1v1i + m2v2i = m1v1f + m2v2f 2 500 = -500 + 3m2 3 000 = 3m2 m2 = 1000 kg WEST AS POSITIVE Σpi = Σpf 1 mark for any (500)(-5) + m2(0) = (500)(1) + m 2(-3) m1v1i + m2v2i = m1v1f + m2v2f -2 500 = 500 - 3m2 -3 000 = -3m2 m2 = 1000 kg (4) [12] TOTAL SECTION A: [50 MARKS] Physical Sciences Controlled Test 1 - 2023 6 SECTION B: CHEMISTRY QUESTION 1 1.1 B (2) 1.2 C (2) 1.3 B (2) [6] QUESTION 2 2.1 A series of organic compounds that can be described by the same general formula and functional group OR 2.2 A series of organic compounds in which one member differs from the next by a CH2 group (2) CnH2n (1) 2.3 Q2.3 Marking criteria • 1 mark for correct functional group • 1 mark for whole structure correct (2) 2.4.1 Alkyl halides (Haloalkanes) (1) 2.4.2 Q2.4.1 Marking criteria • 1 mark for main chain with 6 C’s • 1 mark for methyl and bromo substituent on correct positions. • If condensed or semi-structural Max: 1 mark (2) Q2.5 IUPAC Naming marking criteria • -1 mark for every mistake including numbering, sequence, hyphens and commas 2.5.1 4-ethylhex-2-yne (2) 2.5.2 4-fluro-3,3-dimethylhexane (2) 2.6 M(C3H6O) = 58 g∙mol-1 116 ÷ 58 = 2 Hence molecular formula of ester is C6H12O2 Molecular formula of carboxylic acid is C2H4O2 (if final answer only - award full marks) (3) [15] Physical Sciences Controlled Test 1 - 2023 7 QUESTION 3 3.1.1 3.1.2 3.1.3 The temperature at which the vapour pressure of a liquid is equal to the atmospheric (external) pressure (2) Strength (type) of intermolecular force / Functional group/ Homologous series (1) • • • Butan-1-ol (C) has Hydrogen bonds Butan-2-one (B) has dipole-dipole forces (in addition to London forces) Hydrogen bonds are stronger than the dipole-dipole forces in B OR Dipole-dipole forces are weaker than the hydrogen bonds in C • More energy is required to overcome the intermolecular (hydrogen bonds) in Butan-1-ol (C) OR Less energy is required to overcome the intermolecular/dipole-dipole forces in Butan-2-one (B) (4) 3.1.4 Higher than (1) 3.2.1 p1 = 100 (kPa) / 101,3 (kPa) / 1 atmosphere (1) 3.2.2 Gas . A is above / has past its boiling point (2) 3.2.3 Lower than (1) 3.2.4 Compound C only reached its boiling point at 118 °C where its vapour pressure will equal 101,3 kPa. (2) [14] Physical Sciences Controlled Test 1 - 2023 8 QUESTION 4 4.1.1 Elimination / Dehydrogenation (1) 4.1.2 Substitution (1) 4.1.3 Addition / Hydrohalogenation (1) 4.2.1 Hydration (1) 4.2.2 Butan-2-ol (if butanol or butan-1-ol : only 1 mark) (2) 4.2.3 Sulphuric acid (H2SO4) or phosphoric acid (H3PO4) (1) 4.3.1 Hydrogen bromide 4.3.2 CH3CH=CHCH3 + HBr → CH3CHBrCH2CH3 (do NOT accept HBr – name only) (1) OR CH3CH=CHCH3 + HBr → CH3CH2CHBrCH3 (double bond in but-2-ene can be omitted) If structural or molecular formula max: 2/4 4.4 (4) 2C4H10 + 13O2 → 8CO2 + 10H2O (products)Correct balancing (3) [15] TOTAL SECTION B: [50 MARKS] [TOTAL = 100 MARKS] Physical Sciences Controlled Test 1 - 2023 9 COGNITIVE LEVELS FOR PHYSICAL SCIENCE GRADE 12 – CONTROLLED TEST 2023 COGNITIVE LEVELS 1 QUESTION 2 3 4 Recall Comprehension Analysis Application Evaluation Synthesis (15 %) (40 %) (35 %) (10 %) MARKS SECTION A: PHYSICS 1.1 1.2 1.3 2.1 2.2 2.3.1 2.3.2 3.1 3.2 3.3.1 3.3.2 3.4 3.5 4.1 4.2 4.3 4.4 2 2 2 2 5 4 5 2 1 3 4 3 3 2 3 3 4 2 2 2 2 5 4 5 2 1 3 4 3 3 2 3 3 4 SECTION B: CHEMISTRY 1.1 1.2 1.3 2.1 2.2 2.3 2.4.1 2.4.2 2.5.1 2.5.2 2.6 3.1.1 3.1.2 3.1.3 3.1.4 3.2.1 3.2.2 3.2.3 3.2.4 4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 4.2.3 4.3.1 4.3.2 4.4 2 2 2 2 1 2 1 2 2 2 3 2 1 4 1 1 2 1 2 1 1 1 1 2 1 1 4 3 2 2 2 2 1 2 1 2 2 2 3 2 1 4 1 1 2 1 2 1 1 1 1 2 1 1 4 3 TOTAL 100 13 40 35 12 % 100% 13% 40% 35% 12%