Question

If a body starts from rest and travels $110cm$ in the $9^{th}$ second, then acceleration of the body is:

• A. $0.13m/s^2$
• B. $0.16m/s^2$
• C. $0.18m/s^2$
• D. $0.13m/s^2$

Answer 1

Answer: (A)

The distance travelled by the body in nth second is given by
$s_n=u+\frac{1}{2}a(2n-1)$..(i)
Since, body starts from rest, so $u=0$.
Given, $s_n=110cm,n=9$
Substituting the values in Eq. (i), we get
$110=0+\frac{1}{2}a(2\times 9-1)$
or $110=\frac{a}{2}\times 17$
$\therefore a=\frac{2\times 110}{17}\approx 13cm/s^2$
or $a=0.13m/s^2$