Q. A body falls from rest in the gravitational field of the earth. The distance travelled in the fifth second of its motion is ($g = 10\ m/s^{2}$)
A) $25m$
B) $45m$
C) $90m$
D) $125m$
Explanation
(b) $h_{n} = \frac{g}{2}(2n - 1) \Rightarrow h_{5^{th}} = \frac{10}{2}(2 \times 5 - 1) = 45\ m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.