Question

Two waves travelling in opposite directions along $\pm x$ axis. Their wave equations are expressed as
$y_1=10\cos (\frac{x}{2}+5t)$ and
$y_2=10\cos (\frac{x}{2}-5t)$
where $x$ and $y$ are in $cms$ and $t$ is in $seconds$. After superposition, they form a standing wave. The amplitude at the nodes will be

• A. $0$
• B. $10cm$
• C. $20cm$
• D. $40cm$

Answer 1

Answer: (A)

$0$

Amplitude at nodes is always zero.