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 start - up phase

From \(t = 0\) to \(t=6\) minutes, the heart - rate line is rising, so the heart rate is increasing.

Step2: Analyze the middle phase

From \(t = 6\) to \(t=6 + 19=25\) minutes, the heart - rate line is horizontal, so the heart rate is constant.

Step3: Analyze the ending phase

From \(t = 25\) to \(t=30\) minutes (\(30-25 = 5\) minutes), the heart - rate line is falling, so the heart rate is decreasing.

Answer:

The heart rate increases for 6 minutes, remains constant for 19 minutes, and then gradually decreases for 5 minutes.