Q 11-02-012NEETJEE MainEAMCET 1993 (Engineering)Easy
A particle starts moving from rest under uniform acceleration. It travels a distance $x$ in the first two seconds and a distance $y$ in the next two seconds. If $y = nx$, then $n =$
Answer: (C) $3$
Concept. From rest, $s = \dfrac12at^2$.
Step 1. First $2$ s. $x = \dfrac12a(2)^2 = 2a$.
Step 2. Next $2$ s. First $4$ s: $\dfrac12a(4)^2 = 8a$, so $y = 8a - 2a = 6a$.
Step 3. Ratio. $n = \dfrac{6a}{2a} = 3$. (From rest, distances in equal successive intervals are $1 : 3 : 5 : \dots$)
Answer. $3$ (Option C).
Solution by Sreeraj P, M.Sc Physics