η=[tex] \frac{L}{Q} [/tex]
[tex]q= \frac{Q}{m} =\ \textgreater \ Q=q*m[/tex]
q=45,98 MJ/Kg=45980000 J
Q=45980000*15=689700000 J
19%=[tex] \frac{L}{689700000 } [/tex] <=>0,19=[tex] \frac{L}{689700000 } [/tex]=>L=0,19*689700000 =131043000 J
P=F*v
F=[tex] \frac{P}{v} [/tex]
P=8kW=8000 W
v=63 km/h=17,5 m/s
F=[tex] \frac{8000}{17,5}=457.14 N [/tex]
L=F*d
d=[tex] \frac{L}{F} = \frac{131043000}{457.14} =286658,35 m[/tex]