Answer:
Solution
For figure (a)
During interval AB Velocity is +ve, so the particle is moving in +ve direction, but it is slowing down as acceleration (slope of v-7 curve) is negative.
During interval BC Particle remains at rest as the velocity is zero. Acceleration is also zero.
During interval CD Velocity is -ve, so the particle is moving in -ve direction and is speeding up as acceleration is also negative.
For figure (b),
During interval AB Particle is moving in +ve direction with constant velocity and acceleration is zero.
During interval BC Particle is moving in +ve direction as velocity is +ve, but it slows down until it comes to rest as acceleration is negative.
During interval CD Velocity is -ve so the particle is moving in -ve direction and is speeding up as acceleration is also negatived
