Question

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• A£® ÔÚt=12.0sʱËٶȷ½ÏòˮƽÏòÓÒ
• B£® ÒÀÌâÒâ¿ÉÇóµÃt₀=5.2s
• C£® ÔÚt=6.0sʱËٶȴóСΪ3m/s
• D£® ÔÚt=6.0sʱËٶȴóСΪ1.56m/s

Answer 1

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½âµÃ£º${t}_{1}^{\;}=4.8s$
${a}_{1}^{\;}{t}_{0}^{\;}={a}_{2}^{\;}£¨7.2-{t}_{0}^{\;}£©$
½âµÃ£º${t}_{0}^{\;}=5.2s$£¬¹ÊA´íÎó£¬BÕýÈ·£»
CD¡¢6sÄ©µÄËÙ¶ÈΪ£º${a}_{1}^{\;}{t}_{0}^{\;}-{a}_{2}^{\;}£¨6-5.2£©=1.56m/s$£¬¹ÊDÕýÈ·£¬C´íÎó£»
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