Q. A body is falling freely under gravity. The distances covered by the body in first, second and third minute of its motion are in the ratio
A) 1 : 4 :9
B) 1 : 2 : 3
C) 1 : 3 : 5
D) 1 : 5 : 6
Explanation
(c) Distance covered in a particular time is
$s_{n} = u + \frac{1}{2}g(2n - 1)$
$s_{1} = 0 + \frac{1}{g}(2 \times 1 - 1) = \frac{g}{2}$
$s_{2} = 0 + \frac{1}{2}g(2 \times 2 - 1) = \frac{3}{2}g$
And $s_{3} = 0 + \frac{1}{2}\ g(2 \times 3 - 1) = \frac{5}{2}\ g$
Hence, the required ration is
$s_{1}\ :s_{2}\ :s_{3} = \frac{g}{2}\ :\frac{3}{2}g\ :\frac{5}{2}g$
$\ = 1\ :\ 3\ :\ 5$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.