OnlineCBT
Physics · MOTION IN A STRAIGHT LINE
हिन्दीIn a reaction time experiment using a ruler drop, a person catches a vertically dropped ruler after a displacement of \( d_1 = 20\text{ cm} \). In a second trial under fatigue, the person's reaction time increases by \( 25\% \). What is the distance \( d_2 \) measured on the ruler in the second trial?
Correct answer · Option 3
\( 31.25\text{ cm} \)
Explanation
Reaction distance \( d = \frac{1}{2} g t_r^2 \implies d \propto t_r^2 \). Since \( t_r' = 1.25 t_r \), \( d_2 = (1.25)^2 d_1 = 1.5625 \times 20\text{ cm} = 31.25\text{ cm} \).
