Question

2- Uma pessoa, correndo, percorre 4,0 km com velocidade escalar média de 12 km/h. O tempo do percurso é de: a) 3,0 min b) 8,0 min c) 20 min d) 30 min e) 33 min​

Answer 1

Resposta:

C

Explicação:

ΔS = 4km

Vm = 12km/h

t = ?

Vm = ΔS /Δt

12 = 4 / t

t = 4/12

t = 1/3 h

1h - 60 min

1/3 h - x

x = 20 min

Answer 2

$\large{\begin{array}{l}\sf V=\dfrac{\Delta S}{\Delta t}\Rightarrow\Delta t=\dfrac{\Delta S}{V}\\\\\sf \Delta t=\dfrac{4}{12}\\\\\sf \Delta t\approx0{,}333\,h\\\\\sf 1\,h\rightarrow60\,min\\\sf 0{,}333\,h\rightarrow t\\\\\sf t=\dfrac{60\cdot0{,}333}{1}\\\\\boxed{\boxed{\sf t\approx 20\,min}}\leftarrow\textsf{Letra C}\end{array}}$