From above graph choose correct option for t1 to t2 where t1 is the time at which velocity of particle = 0 t2 is the time at which velocity of particle is negative.
t1=10;t2=17
Particle seems to be at rest at t = 10 sec as even before and after t = 10 sec mark the particle continues to be at 10m displacement from starting point. Thus its displacement doesn't change.
So at t = 10 sec, velocity = 0
Now for the velocity to be negative
Let's analyze the motion of the particle: till time particle moved away from starting point and reached a distance of 10m.
Till t=tc particle stayed there maintaining it displacement of 10m.
Now after tc the particle starts moving towards the starting point as its displacement is decreasing.
So particles velocity was leftwards after t=tc
⇒Particle was moving with a negative velocity in the time instance t = 17 sec, 20 sec, 30 sec etc.