Question

Figure (below) shows a wave pulse at $ t = 0$. The pulse moves to the right with a speed of $ 10 cm {s}^{-1}$. Sketch the shape of the string at $ t = 1 s, 2 s$ and $ 3 s$

Y (in cm) 20 30 40 50 X(incm) 

Answer 1

Step 1. Given data.

Speed of pulse is $v=10cm{s}^{-1}$

Step 2. Sketch the shape of the string at $t=1s,2s$ and $3s$,

We know that, Distance $x=$Speed $v\times$Time $t$

$\Rightarrow$ $x=vt$

At time$t=1s$ the pulse will be at distance $10cm$.

At time $t=2s$ the pulse will be at distance $x=2\times \left(10\right)cm$

$\Rightarrow$ $x=20cm$

At time $t=3s$the pulse will be at distance $x=3\times \left(10\right)cm$

$\Rightarrow$ $x=30cm$

Hence, the shape of the string at $t=1s,2s$ and $3s$ will be as shown in figure.