Question

Q9. Derive the equation for velocity time relation (v=u+at) by graphical method.

Answer 1

Let OE = time, t

Now, from the graph,

BE = AB + AE

⇒ v = DC + OD (Since, AB = DC and AE = OD)

⇒ v = DC + u (Since, OD = u)

⇒ v = DC + u ------------------- (i)

Now, Acceleration (a) =Change in velocityTime taken

⇒a=v−ut

⇒a=OC−ODt=DCt

⇒at=DC

-----(ii)

By substituting the value of DC from (ii) in (i) we get

v=at+u

⇒v=u+at