Respostas

2013-08-22T15:11:57-03:00
A) Velocidade resultante = v_rio + v_barco
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V = 12m/s
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b) V = /\S / /\t

12 = 480 / /\t

480/12 = /\t
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/\t = 40 segundos
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c) V_subida = v_barco - v_rio

V = 4m/s

 480/4 = /\t
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/\t = 120 segundos
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