Date | May 2017 | Marks available | 6 | Reference code | 17M.2.sl.TZ2.7 |
Level | SL only | Paper | 2 | Time zone | TZ2 |
Command term | Justify and Find | Question number | 7 | Adapted from | N/A |
Question
Note: In this question, distance is in metres and time is in seconds.
A particle moves along a horizontal line starting at a fixed point A. The velocity v of the particle, at time t, is given by v(t)=2t2−4tt2−2t+2, for 0⩽t⩽5. The following diagram shows the graph of v
There are t-intercepts at (0, 0) and (2, 0).
Find the maximum distance of the particle from A during the time 0⩽t⩽5 and justify your answer.
Markscheme
METHOD 1 (displacement)
recognizing s=∫vdt (M1)
consideration of displacement at t=2 and t=5 (seen anywhere) M1
eg∫20v and ∫50v
Note: Must have both for any further marks.
correct displacement at t=2 and t=5 (seen anywhere) A1A1
−2.28318 (accept 2.28318), 1.55513
valid reasoning comparing correct displacements R1
eg|−2.28|>|1.56|, more left than right
2.28 (m) A1 N1
Note: Do not award the final A1 without the R1.
METHOD 2 (distance travelled)
recognizing distance =∫|v|dt (M1)
consideration of distance travelled from t=0 to 2 and t=2 to 5 (seen anywhere) M1
eg∫20v and ∫52v
Note: Must have both for any further marks
correct distances travelled (seen anywhere) A1A1
2.28318, (accept −2.28318), 3.83832
valid reasoning comparing correct distance values R1
eg3.84−2.28<2.28, 3.84<2×2.28
2.28 (m) A1 N1
Note: Do not award the final A1 without the R1.
[6 marks]