CBSE Class 9 Answered

1)The graph has been plotted below.

2)Let us take the last part of the graph only.The initial velocity is 10m/s and the velocity drops down to 0 uniformly in 10 sec.Hence the acceleration (a) = (v-u)/t = -1m/s²

The last 5 sec would be start at point A. The velocity of the body at this point would be given by
    V=u+at
    v = 10 +(-1)x5 = 5m/s

The distance then travelled in the last 5 sec would be given by : v² -u² = 2aS

S = (0 - 5²)/(2x(-1))

S = 25/2 = 12.5 m