contestada

A train, 200 m long, travelled through a tunnel at an average speed of 20m/s. The whole train took 2 min 30 sec to pass through the tunnel completely. Find the length of the tunnel in kilometres?

Respuesta :

r3t40

[tex]

l_t=200m \\

s=20\frac{m}{s} \\

t=2\times60+30=150s \\

l=? \\

s=\frac{l}{t}\Longrightarrow l=st \\

l=20\frac{m}{s}\times150s=3000m=\boxed{3km}

[/tex]