Oblicz mase samochodu ek =180kj v =20m/s

Ek = 180 kJ = 180000 J V = 20 m/s m = ? [latex]E_k = frac{mV^2}{2} /* 2 [/latex] [latex]2E_k = mV^2 / : V^2[/latex] [latex]m = frac{2E_k}{V^2} [/latex] [latex]m = frac{2 *180000 J }{(20 frac{m}{s} )^2 } = frac{360000 J }{400 frac{m^2}{s^2} } = 900 kg[/latex] jednostki : [latex][ frac{J}{ frac{m^2}{s^2} } ] = [ frac{N*m}{ frac{m^2}{s^2} } = [ frac{kg * frac{m}{s^2} *m }{ frac{m^2}{s^2} } ] = [ kg ] [/latex]

[latex]E_k= frac{mV^2}{2} \\ 2E_k=mV^2\\ m= frac{2Ek}{V^2} \\ m= frac{2*180000}{20^2}=900 [ frac{J}{( frac{m}{s})^2 } = frac{frac{kg*m^2}{s^2} }{ frac{m^2}{s^2} } =frac{kg*m^2*s^2}{s^2*m^2} =kg ][/latex] liczę na naj M