[tex]dane:\\m = 500 \ g = 0,5 \ kg\\h_1 = 1,2 \ m\\h_2 = 0,8 \ m\\g = 10\frac{N}{kg}\\szukane:\\\Delta E_{w} = ?\\\\Rozwiazanie\\\\\Delta E_{w} = E_{p_1} - E_{p_2}\\\\E_{p} = mgh\\\\\Delta E_{w} = mgh_1 - mgh_2 = mg(h_1-h_2)\\\\\Delta E_{w} = 0,5 \ kg\cdot10\frac{N}{kg}\cdot(1,2 \ m - 0,8 \ m)\\\\\underline{\Delta E_{w} = 2 \ J}[/tex]
Odp. Energia wewnętrzna piłki wzrośnie o 2 J (dżule).