NDA General Ability Question (2025) — Solution

Step-by-step solution

The standard equations of motion for an object moving with constant acceleration are: v = u + at u = v - at s = ut + 1 2 at^2 v^2 - u^2 = 2as S_n = u + 1 2 a(2n-1) Comparing these with the given options: Option (1) matches the second equation of motion. Option (2) is a valid rearrangement of the first equation of motion. Option (3) is given as u^2 - v^2 = 2as, which contradicts the third equation of motion v^2 - u^2 = 2as. Thus, it is incorrect. Option (4) correctly gives the displacement in the n^ th second. Therefore, the incorrect equation is u^2 - v^2 = 2as.