Question

problema 13 din poza de mai jos cu rezolvari

Answer 1

a) v₁²=v₀₁²+2gh₁=0²+2*10*50=1000=>v₁=±√1000=±31,62 m/s

v₁>0=> v₁=31,62 m/s

v₁=v₀₁+gt<=>31,62=0+10t=>t=3,162 s

b)h=h₁-h₂=50-10=40 m

x₂=h+v₀₂t-gt²/2

x₁=h₁-gt²/2

x₁=x₂=>h+v₀₂t-gt²/2=h₁-gt²/2<=>h+v₀₂t=h₁<=>40+3,162v₀₂=50<=>3,162v₀₂=10=>v₀₂=3,16 m/s

c) v₁=31,62 m/s

v₂²=v₀₂²+2gh=3,16²+2*10*40=9,98+800=809,98=>v₂=±√809,98=±28,46 m/s

v₂>0=>v₂=28,46 m/s