s = 240 km = 240000 m t = 2 h = 2 * 3600 s = 7200 s 1 kM ≈ 736 W P = 50 kM * 736 W = 36800 W = 36800 J/s W = ? , F = ? P = W /t W = P * t W = 36800 J/s * 7200 s W = 264960000 J = 264,96 M J ; 1 MJ = 10⁶ J W = F * s F = W /s F = 264960000 J /240000 m F = 1104 N = 1,1 kN ; 1 kN = 10³ N [J/m ] = [ N * m /m ] = [ N ]
dane: s = 240 km = 240 000 m t = 2h = 2 x 3600s = 7200 s P = 50 KM szukane: a) W = ? b) F = ? a) P = W/t I*t W = P x t 1 KM = 736 W P = 50 KM = 50 x 736W = 36 800 W = 36 800 J/s W = 36800J/s x 7200s = 264 960 000 J W = 264,96 MJ ============= b) W = F x s /:s F = W/s = 264960000J/240000m = 1104 J/m = 1104 N F = ok.1,1 kN ============
