Question

Cum se rezolva aceasta problema de cinematica?

Answer 1

d₁=d₃=d/4=100/4=25 m

d₂=d-d₁-d₃=100-25-25=100-50=50 m

v₀=0;v₁=10 m/s

v₁²=v₀²+2ad₁<=>100=0+50a<=>a=2 m/s²

v₁=v₀+at₁<=>10=2t₁=>t₁=5 s

d₂=v₁t₂=>t₂=d₂/v₁=50/10=5 s

v₂²=v₁²+2ad₃=100+2*2*25=100+100=200=>v₂=√200=10√2 m/s

v₂=v₁+at₃<=>10√2=10+2t₃ |:2=>5√2=5+t₃=>t₃=5(√2-1) s

t=t₁+t₂+t₃=5+5+5(√2-1) =10+5(√2-1) =10+5√2-5=5+5√2=5(√2+1) s

t=5(√2+1) s