Date | May 2022 | Marks available | 5 | Reference code | 22M.1.AHL.TZ1.16 |
Level | Additional Higher Level | Paper | Paper 1 | Time zone | Time zone 1 |
Command term | Find | Question number | 16 | Adapted from | N/A |
Question
The wind chill index is a measure of the temperature, in , felt when taking into account the effect of the wind.
When Frieda arrives at the top of a hill, the relationship between the wind chill index and the speed of the wind in kilometres per hour is given by the equation
Find an expression for .
When Frieda arrives at the top of a hill, the speed of the wind is kilometres per hour and increasing at a rate of .
Find the rate of change of at this time.
Markscheme
use of power rule (M1)
OR A1
[2 marks]
(A1)
(M1)
when
(M1)
A2
Note: Accept a negative answer communicated in words, “decreasing at a rate of…”.
Accept a final answer of from use of .
Accept (or ).
[5 marks]
Examiners report
There was some success in using the power rule to differentiate the function in part (a). Many failed to recognize that part (b) was a related rates of change problem. There was also confusion about the term “rate of change” and with the units used in this question.