158- The acceleration–time graph of a moving object whose initial velocity is $+5\,\dfrac{\text{m}}{\text{s}}$ is shown below. What is the average speed of the object during these 12 seconds (in meters per second)? [Figure: $a\,(\text{m/s}^2)$ vs $t(\text{s})$ graph. Acceleration is $+4\,\text{m/s}^2$ from $t=0$ to $t=10\,\text{s}$, then $-2\,\text{m/s}^2$ from $t=10\,\text{s}$ to $t=12\,\text{s}$.] (1) $13.5$ (2) $14$ (3) $27$ (4) $28$
\textbf{158-} The acceleration–time graph of a moving object whose initial velocity is $+5\,\dfrac{\text{m}}{\text{s}}$ is shown below. What is the average speed of the object during these 12 seconds (in meters per second)?
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\textit{[Figure: $a\,(\text{m/s}^2)$ vs $t(\text{s})$ graph. Acceleration is $+4\,\text{m/s}^2$ from $t=0$ to $t=10\,\text{s}$, then $-2\,\text{m/s}^2$ from $t=10\,\text{s}$ to $t=12\,\text{s}$.]}
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(1) $13.5$ \hfill (2) $14$ \hfill (3) $27$ \hfill (4) $28$
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