Question

va rog frumos ! dau coroana

Answer 1

Răspuns:

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Explicație:

$1) \: \:40 \frac{km}{h} = \frac{40}{3.6} \times \frac{m}{s} = 11.(1) \frac{m}{s} \\ \\ 2) \: \: v_b = 18 \frac{km}{h} = \frac{18}{3.6} \times \frac{m}{s} = 5 \frac{m}{s} \\ \\ d = v \times \Delta t \implies \: \Delta t = \frac{d}{v} \implies \Delta t = \frac{30m}{5 \frac{m}{s} } \\ \\ \Delta t = 6s$