Question

The equation of a stationary wave is y = 0.8 cos$\left( \frac{\pi x}{20} \right)$sin 200$\pi t$where x is in cm. and t is in sec. The separation between consecutive nodes will be

• A. 20 cm
• B. 10 cm
• C. 40 cm
• D. 30 cm

Answer 1

Answer: (A)

20 cm

Answer 2

Standard equation y = A cos $\frac{2\pi x}{\lambda}\sin\frac{2\pi vt}{\lambda}$

By comparing this equation with given equation. $\frac{2\pi x}{\lambda} = \frac{\pi x}{20}$

⇒ $\lambda$ = 40 cm

Distance Between two nodes =$\frac{\lambda}{2}$= 20 cm.