Réponse :

Explications :

v = 130 km/h = 130 000 m/h = 13 000 000 cm/h = 13 000 000/3600 cm/s

v = 32500/9 cm/s

d = 50 cm

t = d/v = 50 : 32500/9 = 50 x 9 : 32500 ≈ 0,0138 s