If a car travels $50\mathit{ m}$ distance in $4\mathit{ s}$ with an acceleration of $5\mathit{ m}/\mathit{s²}$, then its initial speed is ___________

If a car travels $50\mathit{ m}$ distance in $4\mathit{ s}$ with an acceleration of $5\mathit{ m}/\mathit{s²}$.
Given : The distance traveled by car $s=50\mathit{ m}$ in time $t=4\mathit{ s}$ with an acceleration of $a=5\mathit{ m}/\mathit{s²}$. 
By the third equation of motion we get,
$s=\mathit{ut}+\frac{1}{2}\mathit{at²}$
Where $s$, $u$, $t$ and $a$ are the displacement, initial velocity, time taken and acceleration of the body respectively.
On substituting the given values, we get the initial velocity as
$\Rightarrow 50=u\times 4+\frac{1}{2}\times 5\times 4²$
$\Rightarrow 50=4u+40$
$\Rightarrow u=2.5\mathit{ m}/s$
Hence, the initial velocity of car is $2.5\mathit{ m}/s$.