Question

The displacement of a wave is given by \( y = 20 \cos(\omega t + 4x) \). The amplitude of the wave is

• A. 10
• B. 20
• C. \( 20\sqrt{2} \)
• D. \( 10\sqrt{2} \)

Hint:

In \( y = A \cos(\omega t + kx) \), the coefficient before cosine is always the amplitude.

Answer 1

The Correct Option is B

In the standard wave equation: \[ y = A \cos(\omega t + kx) \] Where: - \( A \) is the amplitude
- \( \omega \) is angular frequency
- \( k \) is wave number Comparing: \[ y = 20 \cos(\omega t + 4x) \Rightarrow \text{Amplitude} = 20 \]