acceleration/deceleration is quite small (1) Because impact distance is  far (1) Total question = 8 marks Q17. Question Answer Acceptable answers Mark Number (a)(i) substitution (1) 0.8 × 10 × give full marks for correct 1.8 evaluation (1) 14.4 (J) answer, no working (2) Question Answer Acceptable answers Mark Number (a)(ii) 14.4 (J) e.c.f from part (i) (1) Question Answer Acceptable answers Mark Number (a)(iii) substitution (1) 4.8 = 0.8 × allow substitution and v transposition (1) v = transposition in either order 4.8/0.8 evaluation (1) 6 give full marks for correct (m/s) answer, no working (3) Question Indicative Content Mark Number QWC *(b) An explanation linking some of the following points Either momentum item must lose • momentum in order to come to rest force of impact depends • on rate of change of momentum if item is dropped from • greater height then velocity at impact is greater so • momentum to be lost is greater bubble wrap works by • increasing the time taken for the item to come to rest reduces the rate of change • of momentum this reduces • the force of impact to a safe value Or kinetic energy item • must lose kinetic energy in order to come to rest force of • impact depends on work done if item is dropped from • greater height then velocity at impact is greater so kinetic • energy to be lost is greater loss of kinetic energy equals • work done bringing item to rest bubble wrap works by (6) •
acceleration/deceleration is quite small (1)  Because impact distance is far (1) Total question = 8 marks Q17. Question Number Answer Acceptable answers Mark (a)(i) substitution (1) 0.8 × 10 × 1.8 evaluation (1) 14.4 (J) give full marks for correct answer, no working (2) Question Number Answer Acceptable answers Mark (a)(ii) 14.4 (J) e.c.f from part (i) (1) Question Number Answer Acceptable answers Mark (a)(iii) substitution (1) 4.8 = 0.8 × v transposition (1) v = 4.8/0.8 evaluation (1) 6 (m/s) allow substitution and transposition in either order give full marks for correct answer, no working (3) Question Number Indicative Content Mark QWC *(b) An explanation linking some of the following points Either momentum • item must lose momentum in order to come to rest • force of impact depends on rate of change of momentum • if item is dropped from greater height then velocity at impact is greater • so momentum to be lost is greater • bubble wrap works by increasing the time taken for the item to come to rest • reduces the rate of change of momentum • this reduces the force of impact to a safe value Or kinetic energy • item must lose kinetic energy in order to come to rest • force of impact depends on work done • if item is dropped from greater height then velocity at impact is greater • so kinetic energy to be lost is greater • loss of kinetic energy equals work done bringing item to rest • bubble wrap works by (6)
p2_revision_pack_mark_scheme.docx