164. According to the figure below, a body is at rest on a horizontal surface. A horizontal force $F = 40\,\text{N}$ is applied to the body. After $5$ seconds, the force $F$ decreases to $30\,\text{N}$. How does the body move after that? $$\left(g = 10\,\frac{\text{m}}{\text{s}^2}\right)$$ [Figure: A block of $2\,\text{kg}$ on a surface with $F = 40\,\text{N}$ applied horizontally; $\mu_s = 0.6$ and $\mu_k = 0.5$]
[(1)] The body stops at that instant.
[(2)] The body moves with acceleration $1\,\dfrac{\text{m}}{\text{s}^2}$.
[(3)] The body moves with acceleration $2\,\dfrac{\text{m}}{\text{s}^2}$.
[(4)] The body continues moving at constant speed.
\textbf{164.} According to the figure below, a body is at rest on a horizontal surface. A horizontal force $F = 40\,\text{N}$ is applied to the body. After $5$ seconds, the force $F$ decreases to $30\,\text{N}$. How does the body move after that?
$$\left(g = 10\,\frac{\text{m}}{\text{s}^2}\right)$$
\textit{[Figure: A block of $2\,\text{kg}$ on a surface with $F = 40\,\text{N}$ applied horizontally; $\mu_s = 0.6$ and $\mu_k = 0.5$]}
\begin{itemize}
\item[(1)] The body stops at that instant.
\item[(2)] The body moves with acceleration $1\,\dfrac{\text{m}}{\text{s}^2}$.
\item[(3)] The body moves with acceleration $2\,\dfrac{\text{m}}{\text{s}^2}$.
\item[(4)] The body continues moving at constant speed.
\end{itemize}
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