I want also calculation involve in waves in english all

v = λf

v = (2 m) × (10 Hz)

v = 20 m/s  
The **wave speed** is 20 m/s.

**Example**: A sound wave travels at 343 m/s in air and has a wavelength of 0.77 meters.

f = v/λ

f = (343 m/s) / (0.77 m)

f ≈ 445.5 Hz  
The **frequency** is approximately 445.5 Hz.

**Example**: Light travels at 3.0 × 10⁸ m/s. If the frequency of a particular light wave is 6.0 × 10¹⁴ Hz, what is its wavelength?

λ = v/f

λ = (3.0 × 10⁸ m/s) / (6.0 × 10¹⁴ Hz)

λ = 0.5 × 10⁻⁶ m  
λ = 5.0 × 10⁻⁷ m  
The **wavelength** is 5.0 × 10⁻⁷ meters (or 500 nanometers).

**Example**: If a wave has a period of 0.05 seconds, what is its frequency?

f = 1/T

f = 1 / (0.05 s)

f = 20 Hz  
The **frequency** is 20 Hz.

**Example**: Two waves interfere. The path difference between them is 1.5 wavelengths (λ). What is the phase difference?

Δφ = (2π/λ) × Δx

Δφ = 2π × 1.5  
Δφ = 3π radians  
The **phase difference** is 3π radians.

**Example**: Two coherent light sources emit waves that interfere. If the path difference is 400 nm and the wavelength is 800 nm, what type of interference occurs?

Δx / λ = (400 nm) / (800 nm) = 0.5

Since Δx/λ = 0.5, this means Δx = 0.5λ. This fits the condition for destructive interference (n=0, Δx = (0 + 1/2)λ).  
**Destructive interference** occurs.