Question

Let the velocity of an object at time ( t=0)=u (known as the initial velocity)and the velocity of an object at time (=t)= v (known as the final velocity.)
Then, change in the velocity of an object= v-u
Time taken for the change in velocity = t - 0= t
Now, acceleration of the object=
change in velocity of the object/
time taken
acceleration, a=v-u/t
Now my question,
Given t=0
So, a=v-u/t
=v-u/0 which is not defined at all !!!
So, how is acceleration possible in this case??? Please make me understand.
{The contents of this question was taken from the sub-title "Expression for acceleration" of the title "Acceleration" of page -18 of the book "Super Simplified Physics-IX (Term-I)"}
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Answer 1

Let's take an example to understand it well..

suppose a car is in rest ...

so let us suppose that,

initial velocity of that car at( t=1s) =u

final velocity of that car at( t=5s)=v

here,

We'll calculate how much time taken by that car to change the velocity from u to v

so,

Time taken=Final time - initial time =5-1=4sec

And,

Change in velocity=final velocity - initial velocity= v-u

we know that,

acceleration is rate of change of velocity

so,,

a=(change in velocity)÷time taken

=>a=(v-u)÷4

similarly if we take initial time=0 and final time=t

so,

time taken=t-0=t

hence,

a=(v-u)÷t

HOPE YOU UNDERSTAND IT WELL✌️