Velocity is defined as$v=u+5t$, where$u$ is fixed- $5m{s}^{-1}$. Find$v$ at different$t$.

Here, a body is moving with velociy $v=u+5t$ and $u$ is fixed-$5m{s}^{-1}$.
So, putting the value of $u$ in the velocity equation, we get
$v=5+5t$.

Now, the velocity at time $t$ = 0:
$v=5+5\times 0=5+0$ =$5m{s}^{-1}$

Now, the velocity at time $t$ = 1:
$v=5+5\times 1=5+5$ =$10m{s}^{-1}$

Now, the velocity at time $t$ = 2:
$v=5+5\times 2=5+10$ =$15m{s}^{-1}$

Now, the velocity at time $t$ = 3:
$v=5+5\times 3=5+15$ =$20m{s}^{-1}$