Respuesta :

VirαtKσhli

Answer:

15.49 m/s

Explanation:

We know that the stopping distance is ,

=> s = u²/2(-a)

So that ,

=> 20m = u² / 2* 6m/s²

=> u² = 240m²/s²

=> u = √240 m²/s²

=> u = 15.49 m/s

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