Question

The initial velocity of a particle is $10\text{m/sec}$ and its retardation is $2{\text{m/sec}}^2$. The distance covered in the fifth second of the motion will be

• A. $1\text{m}$
• B. $9\text{m}$
• C. $5\text{m}$
• D. $7\text{m}$

Answer 1

The correct option is A $1\text{m}$

Given,
$u=10\text{m/s},a=-2{\text{m/s}}^2,n=5$
As we know that the distance travelled by the particle in $n^{th}$ second is given as
$S_{n^{\text{th}}}=u+\frac{1}{2}\times a(2n-1)$
$=10+\frac{1}{2}\times (-2)(2\times 5-1)$
$=10-9$
$=1\text{m}$