Date | May 2022 | Marks available | 2 | Reference code | 22M.2.SL.TZ2.6 |
Level | Standard Level | Paper | Paper 2 | Time zone | Time zone 2 |
Command term | Determine | Question number | 6 | Adapted from | N/A |
Question
A particle moves in a straight line such that its velocity, , at time seconds is given by .
Determine when the particle changes its direction of motion.
Find the times when the particle’s acceleration is .
Find the particle’s acceleration when its speed is at its greatest.
Markscheme
recognises the need to find the value of when (M1)
(s) A1
[2 marks]
recognises that (M1)
(s) A1A1
Note: Award M1A1A0 if the two correct answers are given with additional values outside .
[3 marks]
speed is greatest at (A1)
A1
[2 marks]
Examiners report
In part (a) many did not realize the change of motion occurred when . A common error was finding or thinking that it was at the maximum of .
In part (b), most candidates knew to differentiate but some tried to substitute in for , while others struggled to differentiate the function by hand rather than using the GDC. Many candidates tried to solve the equation analytically and did not use their technology. Of those who did, many had their calculators in degree mode.
Almost all candidates who attempted part (c) thought the greatest speed was the same as the maximum of .