Question

the graph represents a persons heart rate in beats per minute during 30 minutes of exercise. which statement best describes the relationship between heart rate and time during exercise? the heart rate increases for 6 minutes, remains constant for 19 minutes, and then gradually increases for 5 minutes. the heart rate decreases for 6 minutes, remains constant for 19 minutes, and then gradually increases for 5 minutes. the heart rate increases for 6 minutes, remains constant for 19 minutes, and then gradually decreases for 5 minutes. the heart rate remains constant for 6 minutes, increases for 19 minutes, and then gradually decreases for 5 minutes.

Explanation:

Step1: Analyze the graph

First, look at the time - heart rate relationship. The x - axis is time (in minutes) and the y - axis is heart rate (in beats per minute).
From \(t = 0\) to \(t=6\), the heart rate is increasing.
From \(t = 6\) to \(t=24\) (a duration of \(24 - 6=18\) minutes), the heart rate is constant.
From \(t = 24\) to \(t = 30\) (a duration of \(30 - 24 = 6\) minutes), the heart rate is decreasing.

Step2: Match with the options

Option C: “The heart rate increases for 6 minutes, remains constant for 18 minutes, and then gradually decreases for 6 minutes” matches the analysis of the graph.

Answer:

C. The heart rate increases for 6 minutes, remains constant for 18 minutes, and then gradually decreases for 6 minutes.