[latex]1.\\dane:\m = 500 g = 0,5 kg\h= 4 m\g = 10frac{m}{s^{2}} = 10frac{N}{kg}\szukane:\E_{p} = ?[/latex] [latex]E_{p} = m*g*h\\E_{p} = 0,5kg*10frac{N}{kg}*4m = 20 J[/latex] [latex]2.\dane:\m = 100 kg\W = 200 J\g = 10frac{N}{kg}\szukane:\h = ?[/latex] [latex]W = E_{p} = mgh\\W = mgh /:mg\\h = frac{W}{m*g} =frac{200J}{100kg*10frac{N}{kg}} = 0,2 m[/latex] [latex]3.\dane:\m = 10 t = 10 000 kg\h = 2 km (tutaj zbedne)\v = 200frac{m}{s}\szukane:\E_{k} = ?[/latex] [latex]E_{k} = frac{mv^{2}}{2}\\E_{k} = frac{10000kg*(200frac{m}{s})^{2}}{2} = 200 000 000 J = 200 MJ = 0,2 GJ[/latex] [latex]4.\dane:\U = 20 V\I = 4 A\szukane:\R = ?[/latex] [latex]R = frac{U}{I}\\R = frac{20V}{4A} = 5 Omega[/latex] [latex]5.\dane:\P = 120 W = 0,12 kW\U = 230 V\t = 4h * 30 = 120 h\szukane:\W = ? (kWh)[/latex] [latex]P = frac{W}{t} |*t\\W = P*t\\W = 0,12kW * 120h = 14,4 kWh[/latex]
