Question

A body started with velocity of $10{\text{ms}}^{–1}$ and moving with an acceleration of $1{\text{ms}}^{–2}$. The distance covered by the body in $7^{th}$ second is

• A. $17.5\text{m}$
• B. $16.5\text{m}$
• C. $18.5\text{m}$
• D. $20\text{m}$

Answer 1

The correct option is B $16.5\text{m}$

Given, $u=10{\text{ms}}^{-1},a=1{\text{ms}}^{-2},n=7$
As we know that the distance travelled by a particle in $n^{th}$ second is given as
$s_n=u+\frac{a}{2}(2n-1)$
$\Rightarrow s_{7^{th}}=10+\frac{1}{2}(2\times 7-1)$
$\Rightarrow s_{7^{th}}=10+6.5$
$\Rightarrow s_{7^{th}}=16.5\text{m}$