Per NCERT Example 2.7, REACTION TIME of a person can be measured by which simple experiment?
AHold breath and count
BSolve a maths problem
CDrop a ruler vertically through the gap between fingers; measure the distance d the ruler fell before being caught; compute t = √(2d/g)
DRun a 100 m sprint
Answer & Solution
Correct answer: C. Drop a ruler vertically through the gap between fingers; measure the distance d the ruler fell before being caught; compute t = √(2d/g)
Per NCERT Example 2.7, ruler-drop experiment uses d = ½gt_r² → t_r = √(2d/g).
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