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A person measures their heart rate by counting the number of beats in 30 s. If 40 ± 1 beats are counted in 30.0 ± 0.5 s, what is the heart rate and its uncertainty in beats per minute?

a) 80 ± 2 bpm
b) 80 ± 2 bpm
c) 80 ± 2 bpm
d) 80 ± 2 bpm

User Towkir
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1 Answer

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Final answer:

To calculate the heart rate in beats per minute (bpm), divide the time for one beat (30.0 ± 0.5 s) by the number of beats (40 ± 1), and take the reciprocal of the result. This gives you the heart rate in beats per second. Then, multiply by 60 to convert it to beats per minute.

Step-by-step explanation:

To calculate the heart rate in beats per minute (bpm), we need to find the number of beats per second and then convert it to beats per minute. We can start by finding the average time it takes for one beat:



Time for one beat = (30.0 ± 0.5 s) / (40 ± 1 beats)



Using the given values, we find that the time for one beat is approximately 0.75 seconds per beat. To find the heart rate in beats per minute, we can take the reciprocal of the time for one beat:



Heart rate = 1 / (0.75 s/beat)



Calculating this, we find that the heart rate is approximately 80 beats per minute. Since the uncertainties in the time and beats cancel out in this case, the uncertainty in the heart rate would also be 2 beats per minute. Therefore, the heart rate and its uncertainty in beats per minute is 80 ± 2 bpm.

User Greg Olmstead
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