Q.On an average, a human heart is found to beat 75 times in a minute. Calculate its frequency and period.

The heart completes 75 beats in one minute, so we need the frequency (beats per second) and the period (time for one beat).

Step 1: Convert the rate to standard units.

75 beats per minute = $\frac{75}{60}$ beats per second = $1.25$ beats/s.

Step 2: Frequency is the number of cycles (beats) per unit time.

Step 3: Period is the reciprocal of frequency — the time for one complete cycle. …

Understanding Frequency and Period

When something repeats regularly — a pendulum swing, a wave crest, a heartbeat — we describe its rhythm with two linked quantities.

Frequency tells us how many complete cycles happen in one second. The unit is the hertz (Hz), where $1 \text{ Hz} = 1 \text{ cycle/second}$. A higher frequency means faster repetition.

Period is the time taken for one complete cycle. It's measured in seconds. A shorter period means the event repeats more quickly.

These two are reciprocals:

The heart completes 75 beats in 60 seconds. To find frequency in the standard unit (Hz), we need beats per second. Then the period follows immediately.

Step-by-Step Calculation

1. Convert beats per minute to beats per second.

   The heart beats 75 times in 1 minute, which is 60 seconds. So the number of beats in one second is:

2. Calculate the period from the frequency. …

Step 1: Convert the given rate to a rate per second: $75$ beats per $60\,\text{s}$ gives $\dfrac{75}{60} = 1.25$ beats/s.

Step 2: By definition, frequency $f$ is the number of cycles per second, so $f = 1.25\ \text{Hz}$. …