= 16 m (2 sf) 1 c. they are working against gravity 1 to raise their body 1 and gain potential energy 1 Total /9 a. (i) acceleration negative (or decelerating) 1 2 velocity decreases 1 until it reaches zero 1 (ii) acceleration is positive 1 velocity increases 1 b. v2 = u2 + 2as 1 0 = 122 + 2(-9.8)s 1 s = -144/-19.6 = 7.35 m 1-2 c. v t 1–3 1 mark for starting in positive and decreasing to zero 1 mark for same gradient 1 mark for negative velocity after zero Total /12 a. distance travelled during reaction time: s = vt 1 3 = 16 x 1.2 = 19.2 m 1 distance travelled while stopping: v2 = u2 + 2as 1 = 162 + 2(-8)s 1 = 16 m 1 Total distance= 19.2 + 16 = 35.2 m 1 b. reaction force braking force air resistance gravity 2 marks for gravity and reaction force in opposite directions, and equal size 1–4 1 mark for braking force larger than air resistance 1 mark for air resistance in same direction as braking force
= 16 m (2 sf) 1 c. they are working against gravity to raise their body and gain potential energy 1 1 1 Total /9 2 a. (i) acceleration negative (or decelerating) velocity decreases until it reaches zero (ii) acceleration is positive velocity increases 1 1 1 1 1 b. v2 = u2 + 2as 0 = 122 + 2(-9.8)s s = -144/-19.6 = 7.35 m 1 1 1-2 c. v t 1 mark for starting in positive and decreasing to zero 1 mark for same gradient 1 mark for negative velocity after zero 1–3 Total /12 3 a. distance travelled during reaction time: s = vt = 16 x 1.2 = 19.2 m distance travelled while stopping: v2 = u2 + 2as = 162 + 2(-8)s = 16 m Total distance= 19.2 + 16 = 35.2 m 1 1 1 1 1 1 b. reaction force braking force air resistance gravity 2 marks for gravity and reaction force in opposite directions, and equal size 1 mark for braking force larger than air resistance 1 mark for air resistance in same direction as braking force 1–4
Physics_ATAR_Y11_sample_assessment_tasks_WACE_201516.docx