Question

Problemele 6 si 8 va rog

Answer 1

6.

v₀=108 km/h=30 m/s

v=v₀+aΔt<=>0=v₀+30a=>a=-30/30=-1 m/s²

v²=v₀²+2as=>s=-v₀²/2a=v₀Δt/2=30*30/2=450 m

vm=(v+v₀)/2=(0+30)/2=15 m/s

8.

x=x₀+v₀t+at²/2<=>x=v₀t+at²/2=>a=2(x-v₀t)/t²=0,3 m/s²

v=v₀+at=16 m/s

x₁=v₀t₁+at₁²/2=>at₁²/2+v₀t₁-x₁=0=>t₁=(-v₀+√(v₀²+2ax₁))/a=15 s

v₁=v₀+at₁=8,5 m/s

vm=(v₀+v₁)/2=6,25 m/s