Respuesta :

Answer:

3.5 s

Explanation:

Time,[tex]t=\frac {d}{s}[/tex]

Where d is the distance covered and s is the speed.

Substituting 42 m for distance and 12 m/s for speed then

[tex]t=\frac {d}{s}=\frac {42}{12}=3.5 s[/tex]