Practice question

Given: A stone is dropped from a height of 122.5 m . How long does it take to reach the ground? (Take g = 10 m/s² ) Formula: For free fall, use y = 1/2 g t². Substitution & Calculation: Here, y = 122.5 m, g = 10 m/s² . Substitute: 122.5 = 1/2 · 10 · t² Rightarrow 122.5 = 5 t² Rightarrow t² = 24.5 Rightarrow t = √24.5 approx 4.95 s . Rounded to one decimal, the time is 5 s . Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.