Question

- The heart of a man beats $75$ times a minute. What is its time period?
A) $0.75s$
B) $1.33s$
C) $1.24s$
D) $0.8s$

Answer 1

Hint: To calculate the frequency in hertz, we have to measure the time in seconds.
That is, $t$ = $1$ minute = $60$ seconds.
Number of times it beats $= 75$ times per minute.

Complete step by step answer:
To calculate the frequency in hertz. We have to measure the time in seconds. That is, $t = 1$ minute =$60$ seconds. Number of times it beats =$75$ times per minute.
Frequency is givens as,
Number of times it beats/Total time taken in seconds =$75/60 = 1.25Hz.$ Hence, the frequency of a man’s heartbeats is $1.25$ times per second. The time period is given as the inverse of frequency that is,
$T = \dfrac{1}{f} = \dfrac{1}{{1.25}} = 0.8\sec $
Hence, the time period of a man’s heart beat is $0.8\sec $.

Additional Information:
The heart is a hollow muscular fish shaped organ about the size of a close fist its located approximately in the center of the chest. The average adult human heart weighs about $300$ grams in men and about $200$ grams in women. Human heart begins beating or contracting early in petal life, a continuous regular beating throughout the lifespan, Stopping only at the time of death.
About $50$ million gallons of blood pass through the heart in an average lifetime. The heart beats about $70$ times per minute at rest in adults and from $90$ to $140$ times in infants smaller heart pumps less blood with every beat that larger heart. As a result, smaller hearts need to increase their pumping capacity over time, a task they accomplished by beating faster.
When a person is nervous or performs some kind of physical activity, the heartbeat speeds up.
To get the period between heartbeat, $1$ minute or $60$ second must be divided by the number of beats per minute for example, If the heart beats $70$ times per minute, we divide $60$ second by $70$.
A normally performing heart must be fully expanded before it can efficiently pump again. Assuming a healthy heart and a typical rate of $70$ to $75$ beats per minute, each cardiac cycle or heartbeat takes about $0.8$ second to complete a cycle.

So, the correct answer is “Option D”.

Note:
Beats per minute (BPM – Rotation speed), frequency beats per minute(BPM) is a unit typically used as either a measure of tempo in music or a measure of one’s heart rate of $60bpm$ means that one beat will occurs every second one bpm is equal to $1/60Hz$.