| Date | November 2012 | Marks available | 1 | Reference code | 12N.3.SL.TZ0.4 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Estimate | Question number | 4 | Adapted from | N/A |
Question
The data in the graph was obtained from a physically fit rower using a calibrated rowing machine and a heart rate monitor.
The table shows cardiac output during exercise for an untrained person.
Estimate, using the graph, the resting heart rate of the physically fit rower.
Estimate, using the graph, the increase in heart rate between exercise at 25 watts and 250 watts. (Show your workings.)
Predict, with a reason, whether the increase would be greater or less in an untrained person when the power output increases from 25 watts to 250 watts.
Markscheme
60 (beats min–1) (accept answers in the range of 58 to 64 (beats min–1))
(heart) rate 80 (at 25 W) and (heart) rate 140 (at 250 W) (difference =)
60 (beats min–1) (both needed)
greater as trained rower should have larger stroke volume / each (heart) beat more efficient / OWTTE (accept converse)
Examiners report
Most candidates correctly used the graph in (a) to find the resting heart rate.
The calculation in (b) (i) was an easy mark for many candidates.
Many candidates gave vague answers for part (ii). Simply referring to the fact that the person was untrained and therefore not used to exercise. Reference in b (ii) needed to be made to stroke volume or efficiency of each heartbeat.
