Question

站臺上有一觀察者，在火車開動時站在第1節(jié)車廂前端的附近，第1節(jié)車廂在5 s內(nèi)駛過此人．設(shè)火車做勻加速運(yùn)動，求第10節(jié)車廂駛過此人需多長時間?

Answer 1

0.81 s

解析：設(shè)每節(jié)車廂長為x₀，根據(jù)x=v₀t+at²有：x₀=at₁₀²                        ①

10x₀=at₁₀²                                                                                         ②

9x₀=at₉²                                                                                             ③

Δt=t₁₀-t₉                                                                                                 ④

聯(lián)立①②③④式解得：Δt=（）t₁=0.81 s．