iran-konkur 2018 Q180

iran-konkur · Other · konkur-riazi_1397_specialized Variable acceleration (1D) True/false or multiple-statement verification
180. The equation of motion of a body in SI is $x = 2t^3 - 6t^2 + 6t$ . In the time interval zero to 2 seconds, which statement is correct?
  1. [(1)] Average acceleration is equal to zero.
  2. [(2)] The direction of motion changes once.
  3. [(3)] The motion is first decelerating and then accelerating.
  4. [(4)] The motion is initially in the direction of the $x$-axis and then opposite to the $x$-axis.
\textbf{180.} The equation of motion of a body in SI is $x = 2t^3 - 6t^2 + 6t$ . In the time interval zero to 2 seconds, which statement is correct?

\begin{enumerate}
\item[(1)] Average acceleration is equal to zero.
\item[(2)] The direction of motion changes once.
\item[(3)] The motion is first decelerating and then accelerating.
\item[(4)] The motion is initially in the direction of the $x$-axis and then opposite to the $x$-axis.
\end{enumerate}