Question

The velocity of a body moving with a uniform acceleration of $2m{s}^{-2}$ is $10m{s}^{-1}$. What is its velocity after an interval of $4$ second?

Answer 1

Step 1: Given

Acceleration, $a=2m{s}^{-2}$

Initial velocity, $u=10m{s}^{-1}$

Time, $t=4sec$

Step 2: Formula

According to the first equation of motion,

$v=u+at$

where, $u$ is initial velocity, $v$ is final velocity, $a$ is acceleration and $t$ is time.

Step 3: Calculation:

Substituting the value of $a=2m{s}^{-2}$, $u=10m{s}^{-1}$ and $t=4sec$ in $v=u+at$,

$v=u+at$

$\Rightarrow v=10+\left(2\right)\left(4\right)$

$\Rightarrow v=10+8=18m{s}^{-1}$

Hence, the velocity after an interval of $4$ seconds is $18m{s}^{-1}$.