Question

A train starts from rest and accelerate uniformly at the rate of $5{\text{m/s}}^2$ for $5\text{sec}$. Calculate the velocity of train in $5\text{sec}$.

• A. $20\text{m/s}$
• B. $25\text{m/s}$
• C. $10\text{m/s}$
• D. $5\text{m/s}$

Answer 1

The correct option is B $25\text{m/s}$

As the train starts from rest, initial velocity of the train, say, $v_i=0$
Let the velocity of train be $v$ in $5\text{s}$
Then, we have
Acceleration of the train is given by
$a=\frac{\Delta v}{\Delta t}=\frac{v-v_i}{5}\Rightarrow 5=\frac{v-0}{5}$
$\Rightarrow v=25\text{m/s}$