Question

Va rog macar primele 2

Answer 1

$1.\\L_G=mgh=10*5*10=500 J\\h'=\frac{h}{2}=\frac{5}{2} =2,5 m\\E_p=mgh'=10*10*2,5=250 J\\v^2=2gh'=2*10*2,5=50 m^2/s^2\\E_c=\frac{mv^2}{2}=\frac{10*50}{2}=250 J\\ E=E_c+E_p=250+250=500 J\\v_f^2=2gh=2*5*10=100=>v_f=\sqrt{100}=10 m/s\\\\2.\\E_p=mgh=>h=\frac{E_p}{mg}=\frac{250}{5*10}=5 m$