Date | November 2020 | Marks available | 1 | Reference code | 20N.1.SL.TZ0.T_12 |
Level | Standard Level | Paper | Paper 1 (with calculator from previous syllabus) | Time zone | Time zone 0 |
Command term | State | Question number | T_12 | Adapted from | N/A |
Question
Jean-Pierre jumps out of an airplane that is flying at constant altitude. Before opening his parachute, he goes through a period of freefall.
Jean-Pierre’s vertical speed during the time of freefall, S, in m s-1, is modelled by the following function.
S(t)=K-60(1.2-t) , t≥0
where t, is the number of seconds after he jumps out of the airplane, and K is a constant. A sketch of Jean-Pierre’s vertical speed against time is shown below.
Jean-Pierre’s initial vertical speed is 0 m s-1.
Find the value of K.
In the context of the model, state what the horizontal asymptote represents.
Find Jean-Pierre’s vertical speed after 10 seconds. Give your answer in km h−1 .
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure. It appeared in a paper that permitted the use of a calculator, and so might not be suitable for all forms of practice.
0=K-60(1.20) (M1)
Note: Award (M1) for correctly substituted function equated to zero.
(K=) 60 (A1) (C2)
[2 marks]
the (vertical) speed that Jean-Pierre is approaching (as t increases) (A1) (C1)
OR
the limit of the (vertical) speed of Jean-Pierre (A1) (C1)
Note: Accept “maximum speed” or “terminal speed”.
[1 mark]
(S=) 60-60(1.2-10) (M1)
Note: Award (M1) for correctly substituted function.
(S=) 50.3096… (m s-1) (A1)(ft)
Note: Follow through from part (a).
181 (km h-1) (181.114… (km h-1)) (A1)(ft) (C3)
Note: Award the final (A1)(ft) for correct conversion of their speed to km h−1.
[3 marks]