JEE PYQ: Waves And Sound Question 45
Question 45 - 2019 (12 Jan Shift 2)
A travelling harmonic wave is represented by the equation $y(x,t) = 10^{-3}\sin(50t + 2x)$, where $x$ and $y$ are in meter and $t$ is in seconds. Which of the following is a correct statement about the wave?
(1) The wave is propagating along the negative x-axis with speed 25 ms$^{-1}$.
(2) The wave is propagating along the positive x-axis with speed 100 ms$^{-1}$.
(3) The wave is propagating along the positive x-axis with speed 25 ms$^{-1}$.
(4) The wave is propagating along the negative x-axis with speed 100 ms$^{-1}$.
Show Answer
Answer: (1)
Solution
Comparing the given equation $y = 10^{-3}\sin(50t + 2x)$ with standard equation, $y = a\sin(\omega t + kx)$
$\Rightarrow$ wave is moving along $-$ve x-axis with speed
$v = \frac{\omega}{K} = \frac{50}{2} = 25$ m/sec.
BETA
