Maximum distance apart from both cars before Car B catches up with Car B

[cyy91]

Homework Statement

Car A travel at uniform velocity at 20 metre per second from t=0s.
Car B starts with 5 metre per second during t=0s and accelerates uniformly to 30 metre per second in t=30s.It travels at constant velocity of 30 metre per second from there onwards

Homework Equations

The Attempt at a Solution

A velocity-time graph is plotted for this question.

But i just simply don't know wad to do regarding the maximum distance between both of the cars before Car B catches up with Car A.
I need urgent help and i mean it,thanks...
what can i do with the graph to solve this question?

 

[tiny-tim]

Welcome to PF!

Hi cyy91! Welcome to PF!

The distance between the cars at any time is the horizontal distance between the two graphs at that value of t.

There are no curves … the graphs is only straight lines … and two straight lines either get continually further apart, or continually closer together … so the maximum distance must be at one of the "joins".

 

[cyy91]

thx a lot...understood...