Question

The initial velocity of a body moving along a straight line is $7\text{m/s}$. It has a uniform acceleration of $4{\text{m/s}}^2$. The distance covered by the body in the $5^{\text{th}}$ second of its motion is

• A. $25\text{m}$
• B. $35\text{m}$
• C. $30\text{m}$
• D. $15\text{m}$

Answer 1

The correct option is A $25\text{m}$

Given, $u=7\text{m/s},a=4{\text{m/s}}^2,n=5$
As we know that the distance travelled by a particle in $n^{th}$ second is given as
$S_n=u+\frac{a}{2}[2n-1]$
$\Rightarrow S_{5^{\text{th}}}=7+\frac{4}{2}[2\times 5-1]=7+18=25\text{m}$