h=300m V=72km/h=72 * 1000m/3600s=20m/s m=2kg g≈10m/s² Ep=m*g*h Ep=2kg*10m/s²*300m Ep=6000J Ek=½*m*v² Ek=½*2kg*(20m/s)² Ek=400J Emech=Ep+Ek Emech=6000J+400J Emech=6400J
[latex]h = 300m[/latex] [latex]m = 2kg[/latex] [latex]v = 72 frac{km}{h} = 20 frac{m}{s}[/latex] [latex]g = 10 frac{m}{s^2}[/latex] ___________________ [latex]Ep = ?[/latex] [latex]Ek = ?[/latex] [latex]Em = ?[/latex] [latex]Ep = mgh = 2kg cdot 10 frac{m}{s^2} cdot 300m = 6000J = 6kJ[/latex] [latex]Ek = frac{mv^2}{2} = frac{2kg cdot (20frac{m}{s})^2}{2} = 400J = 0,4kJ[/latex] [latex]Em = Ep + Ek = 6000J + 400J = 6400J = 6,4 kJ[/latex]
