Aperson measures his or her heart rate by counting the number of beats in 30s. if 40±1 beats are counted in 30.0±0.5s, what is the heart rate and its uncertainty in beats per minute?

Heart rate=80 beats per minute

Uncertainty=3 beats per minute

Explanation:

We are given that a person measures heart beat by counting the number of beats in 30 s.

If number of beats=

Time=

We have to find the heart rate and its uncertainty in beats per minute

Maximum number of beats=40+1=41

Minimum time=30.0-0.5=29.5 s

Because when heart beat increases then time reduces.

We know that 1 minute =60 seconds

Therefore, time =

Average number of beats=40

Average time=30 seconds=

Heart rate =

Heart  rate =

Maximum heart rate=

When minimum number of beats=40-1=39

Maximum time=30.0+0.5=30.5 seconds

Because when heart beat slow then it takes more times

Time=

Minimum heart rate=

Uncertainty when heart rate is maximum

Uncertainty=83.33-80=3.33 beats per minute

Uncertainty when heart rate is minimum

Uncertainty=80-76.77=3.23 beats per minute

Average uncertainty=

Average uncertainty=3.28 beats per minute

Hence, heart rate=80 beats per minute

Uncertainty=3 beats per minute