The graph between the displacement $x$ and time $t$ for a particle moving in a straight line is shown in figure. During the interval $OA,\,AB,\,BC$ and $t = 1,\;{v_x} = 0$, the sign of acceleration of the particle at $OA, AB, BC, CD$ is respectively
A
$+ \,\, 0\,\, + \,\, +$
B
$- \,\,0 \,\,+ \,\, 0$
C
$+ \,\, 0\,\, -\,\, +$
D
$-\,\,0 \,\, - \,\, 0$
The graph between the displacement $x$ and time $t$ for a particle moving in a straight line is shown in figure. During the interval $OA,\,AB,\,BC$ and $t = 1,\;{v_x} = 0$, the sign of acceleration of the particle at $OA, AB, BC, CD$ is respectively
Region $OA$ shows that graph bending toward time axis i.e. acceleration is negative.
Region $AB$ shows that graph is parallel to time axis i.e. velocity is zero. Hence acceleration is zero.
Region $BC$ shows that graph is bending towards displacement axis i.e. acceleration is positive.
Region $CD$ shows that graph having constant slope i.e. velocity is constant. Hence acceleration is zero.