v₀=0
1) t=3 s=>v'=v₀+gt=0+10*3=30 m/s=>v'=30 m/s
2) t∈[2,3] s
h₁=v₀t₁+gt₁²/2=0*2+10*2²/2=5*4=20 m
h₂=v₀t₂+gt₂²/2=0*3+10*3²/2=5*9=45 m
Δh=h₂-h₁=45-20=25 m=>Δh=25 m
3)h=v₀t+gt²/2<=>250=0+5t²<=>t²=50=>t=√50=7,07 s≅7 s
t'∈[6,7] s
h₁'=v₀t₁'+gt₁'²/2=0*6+10*6²/2=5*36=180 m
h₂'=v₀t₂'+gt₂'²/2=0*7+10*7²/2=5*49=245 m
Δh'=h₂'-h₁'=245-180=65 m=>Δh=65 m
4) v=v₀+gt=0+10*7=70 m/s=>v=70 m/s
5)h'=h/2=250/2=125 m
h'=v₀t'+gt'²/2<=>125=0+10t'²/2<=>125/5=t'²=>t'²=25=>t'=√25=5 s=>t'=5 s
