A ruler is dropped vertically and caught after different reaction times. A: 0.20 s; B: 0.22 s; C: 0.18 s; D: 0.19 s; E: 0.21 s. Take g = 9.8 m·s⁻². Arrange the fall distances in descending order.
Options

Question

A ruler is dropped vertically and caught after different reaction times. A: 0.20 s; B: 0.22 s; C: 0.18 s; D: 0.19 s; E: 0.21 s. Take g = 9.8 m·s⁻². Arrange the fall distances in descending order.

G1 Physics · Accepted Answer

Step 1: A ruler released from rest falls a distance d = ½gt² under uniform gravitational acceleration. Step 2: g is identical for all cases, so d ∝ t². Longer reaction time means larger drop distance. Step 3: Sort the times: B = 0.22 s > E = 0.21 s > A = 0.20 s > D = 0.19 s > C = 0.18 s. Step 4: Their fall distances follow the same order. Final answer: B > E > A > D > C (Option D).