Question

A car starting from rest & moves for 20 seconds its velocity reach 5 m/s & moves at this velocity for 30 seconds.its velocity increases to 10 m/s over 10 seconds.it moves at this velocity for 40 seconds & then slows down to come to rest after further 60 secnds.draw velocity-time graph for the car's journy

Answer 1

stage 1: a = 4 m/s^2
stage 2: a = 0
stage 3: a = 1/2 m/s^2
stage 4: a=0
stage 5: a = -1/6 m/s^2
For each stage, the acceleration is the slope of the graph.

Answer 2

It's not clear

Answer 3

stage 1
v = v initial + a t
v = 0 + a t
5 = 20 a
a = (1/4) m/s^2
so v = 0.25 t for the first 20 seconds, t = 0 to t = 20
stage 2
v = constant 5 m/s from t = 20 to t = 50
etc