Respostas

2014-06-30T14:50:55-03:00
Fr = 12 N
m = ?
V₀ = 0
V = 18/6 = 3 m/s
Δt = 6 s

Ir = FrΔt ⇒ Q - Q₀ = FrΔt ⇒ mV - mV₀ = FrΔt⇒ m(V - V₀) = FrΔt
m = FrΔt/(V - V₀) ⇒ m = (12 · 6)/(3 - 0) ⇒ m = 72/3 ⇒ m = 24 kg