Question

A pendulum completes 20 oscillations in 40 seconds. What is its frequency?

• A. 0.5 Hz
• B. 2 Hz
• C. 20 Hz
• D. 40 Hz

Hint:

Frequency is the reciprocal of time period: \[ f = \frac{1}{T}, \quad \text{or more generally,} \quad f = \frac{\text{number of oscillations}}{\text{time}}. \]

Answer 1

The Correct Option is A

Step 1: Understand the definition of frequency.
Frequency (\( f \)) is defined as the number of complete oscillations per unit time: \[ f = \frac{n}{t} \] where:
\( n = 20 \) oscillations,
\( t = 40 \) seconds.
Step 2: Substitute values. \[ f = \frac{20}{40} = 0.5 \, \text{Hz} \] Hence, the frequency of the pendulum is 0.5 Hz.