Question

a pendulum makes 20 oscillations in one second.calculate it's frequency in hz.

Answer 1

Number of oscillations in unit time is called frequency.
If it makes 20 oscillations in 1 second. then its frequency is 20Hz.

Answer 2

Answer:

A pendulum makes 20 oscillations in one second. Its frequency is $20Hz$

Explanation:

• The number of oscillations completed per time is the frequency of oscillation. It can be expressed as,  

        $Frequency = \frac{No\ of\ oscillations}{time\ taken}$

• Let f be the frequency of oscillation and N be the number of oscillations completed in time t.

         So as per definition,

        $f = \frac{N}{t}$                            ...(1)

• In the question, it is given that,

        Number of oscillations                   $=20$

        Time is taken for the oscillations   $=1s$

• Then using equation(1),

         Frequency = $\frac{20}{1} =20 Hz$