A particle is moving along $X$-axis with velocity $v=e^{-\beta x}$. At time $t=0$, the particle is located…
- $e^{-\beta t}$
- $\frac{1}{\beta} e^{(1-\beta t)}$
- $\frac{1}{\beta} \log [1-\beta t]$
- $\frac{1}{\beta} \log [1+\beta t]$
Solution

$\Rightarrow$ Integrating, we get $\int_0^x e^{\beta x} d x=\int_0^t d t$ $\begin{aligned} & \Rightarrow \quad \frac{1}{\beta}\left[e^{\beta x}\right]_0^x=[t]_0^t \\ & \Rightarrow \quad \frac{1}{\beta}\left(e^{\beta x}-e^0\right)=t-0 \Rightarrow \frac{1}{\beta}\left(e^{\beta x}-1\right)=t\end{aligned}$ $e^{\beta x}=\beta t+1$ Taking log, we get $\log \left(e^{\beta x}\right)=\log (\beta t+1)$ $\begin{array}{ll}\Rightarrow & \beta x=\log (\beta t+1) \\ \Rightarrow & x=\frac{1}{\beta} \cdot \log (\beta t+1)\end{array}$ So, displacement function for the particle is $x=\frac{1}{\beta} \cdot \log (\beta t+1)$
Asked in: AP EAMCET 2022 (07 Jul Shift 1)