A-LevelMathematicsMechanics9709/41 · May/June 2017 · Q57 Marks
A particle P moves in a straight line ABCD with constant deceleration. The velocities of P at A, B and C are 20 m s⁻¹, 12 m s⁻¹ and 6 m s⁻¹ respectively.
- (i)Find the ratio of distances AB : BC.[4]
- (ii)The particle comes to rest at D. Given that the distance AD is 80 m, find the distance BC.[3]
Mark scheme
Marking points from the official mark scheme (May/June 2017). The mark or mark type is shown in brackets.
- [12² = 20² – 2a × AB; 6² = 12² – 2a × BC]
- AB = 128/a
- BC = 54/a
- AB : BC = 64:27
- 0 = 20² – 2a × 80 → a = 2.5
- BC = 54/2.5
- BC = 21.6 m
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →